Since I own both of these packs I figured I'd pass along a review of the two considering they are quite similar in a number of areas. In terms of sizes and specs, I've included the links below for those who wish to debate the merits of 60-70 grams and a litre here and there, in my view they are roughly the same size in terms of volume, with a nod going to the Crown for a bit more room. However this review is based on the performance of the packs, not the specs, features or price. As far as myself, I worked in the outdoor industry for about a decade years ago, specifically with packs, and was a product tester for the likes of Arc'Teryx, Dana Design (RIP) and Gregory. I've also carried Osprey and ULA packs for many hundreds of miles. So, my industry knowledge, including pack design and fit, means I tend to focus almost entirely on performance and design rather than features. Whether or not it's easy to access a water bottle has no impact on the performance of the pack, so things like that are not mentioned because there are plenty of those reviews all over the internet. What matters most with a pack is whether or not it fits me and how it carries the weight. If those two things are positive then the pack is almost always going to "feel good".
https://www.ula-equipment.com/product_p/circuit.htm - ULA Circuit
http://www.granitegear.com/crown2-60-pack-2615.html - Granite Gear Crown 2
Context - I have limited experience with the Crown 2 compared to the Circuit, however the good thing about packs is that they don't really 'break in' all that much, hardly at all really. Sure, foams soften up and eventually break down, but after many years of hard use. So I feel that I have enough miles on the Crown with weight to make a robust judgement on it's performance.
Style of pack - it's a little unfair to put these two packs side by side since the Crown is essentially frameless, while the Circuit has a fairly robust internal frame. However outside of that very big difference they are fairly similar in terms of size, weight, intended use, weight recommendations and price, so I figured it would be worthwhile to compare them as I could easily see people having a hard time choosing between the two.
Suspension - as mentioned above, the Circuit is the clear winner here simply because it comes with both an internal vertical aluminum stay and carbon fiber struts that run alongside the pack, connected with a Delrin hoop that bows across the top. So the Circuit can handle more weight and has the ability to carry it to the hips far better than the more or less 'frameless' Crown. I long ago removed the internal stay in the Circuit as it's completely overkill for a pack that size, so even just leaving the struts is plenty for my needs in terms of getting that weight down on the hips. Now, the Crown claims it has a 'frame' however all it is a stiffened HDPE or Polypropylene framesheet that has molded sections to increase it's vertical integrity, meaning it's more stiff than just a plastic sheet that can be easily folded in half (like the original VC Crown 60). Clearly, people asked for a stiffer framesheet in the VC Crown so they eventually complied when coming out with the Crown 2. However, it baffles me why they wouldn't sew a stay sleeve into the damn thing and simply allow the user to remove the stay (like the Circuit does). In my mind this is a huge flaw, but it is what it is. Saying that, the Crown carries very well for a limited frame, provided you're wearing the correct size, have the pack jammed full, and have all the compression straps tight. The combination of the foam backpanel, the stiffened framesheet, with all your gear compressed against one side of the framesheet, with your back on the other side - leaves very little space for the pack to collapse, as most frameless packs tend to do. This will happen however if the pack isn't fill to capacity, as the extra space in the pack WILL result in some collapse, with the user picking up more weight in the shoulders. Keep in mind that all packs work best when full with nothing attached outside, however with the Crown, you're going to need to pay more attention to this than you would have to with the Circuit. So all in all, if you tend to be on the wrong side of 12kg (25lbs), the Circuit will handle that weight better in terms of 'transfer'. However with 8-12kg, in my experience the Crown carries it well to the hips, just not as good as the Circuit. What this means in plain English is that you'll feel more weight in your shoulders with the Crown than you will in the Circuit, whether this is good or bad is up to you. For most hikers, this would be considered a negative.
Components - people often mistakenly refer to the hipbelt and shoulder harness (straps) as suspension. The suspension is what gets weight from A to B - the frame - the hipbelt and shoulder straps simply 'hold' weight, they do nothing in terms of weight transfer. Now this is where personal preference comes in, because everyone is shaped differently, however when I share my views I also keep in mind the many hundreds of pack fits I've done, so I'm also considering the 'average' person in addition to my personal opinion. In terms of foam integrity, both packs use good, thin, pliable and most important rigid foams that support the weight well. However, there is no question in my mind that ULA comes up short in their 'cut' and 'cant' of both the shoulder straps and hipbelt. ULA has since introduced a 'S shaped' shoulder strap option, I've never used those and can only assume I would like them better, but the straps I have (J strap) are still shipped as standard components with all their packs. I personally like the foam density in the ULA shoulder strap better, but never liked the cut and it's relative flat cant (angle, slope). I doubt many people would find it more comfortable compared to something like a Granite Gear or Osprey (I've always felt Osprey has the best cut shoulder strap I've ever seen), also the ULA shoulder straps are sewn 8cms apart from each other, and the width of the actual pad is 7cms, in my experience they are set too wide and the pads are too wide for the typical person. The Crown on the other hand has a stiffer, but far better cut shoulder strap, which is narrower, and set closer together on the pack, so I naturally like it better and I think most people would as well. If someone was really big and broad, the ULA would be the better choice however. On the hipbelts, while the ULA offers 4 sizes and is stiffer and more supportive, again I've always found the cut and cant lackluster. So again I would side with the Crown in terms of feel, which is personal preference, however from my experience packfitting I'd say 'most' people would prefer the Crown components to the ULA if I were a betting man.
Compression - a very underrated feature of packs because of how much it impacts on the pack's ability to perform well. The Crown blows the Circuit away in this department, but it also NEEDS to have great compression do to the compression dependent framesheet, so that is to be expected. The Circuit has a top compression strap, and ONE horizontal one towards the top of the pack on each side - that's it! ULA claims the bungy on the back of the pack aids in compression (it does a tad) but there's no question this is a weakness. The Crown has two side compression straps on each side, two on the rear, and two going over the top (to a single point).
Stability - as to be expected, the more flexible (and less supportive) Crown moves better due to less internal structure and better torsion flex (left to right), however it's not a major difference and this is only apparent when the Circuit is jammed full, otherwise I really like the way the Circuit moves as well. I'd call this a draw.
Heat - both are up against your back, snug, and there will be little airflow. The Crown is better ventilated with holes and channels cut out however in practice it accomplishes very little, because on the other side of those holes is all your gear which blocks airflow anyhow, so it's a gimmick in my experience. I would say on paper the Crown is 'cooler' on the back but I can't notice a difference. The only way to gain airflow is to physically push the pack away from your back, like an external frame or what Osprey and Zpacks are doing these days in many designs. The issue with those is that you lose surface area, some stability and you push the weight out further away from your back - just personal preference however I've never liked the feel of those designs, and while seemingly new, have been around since the early 90's by various manufacturers.
Overall - I'm glad I have both packs and do see them as different packs for different uses to some degree. The Circuit is a proven, trail tested pack with many accolades, and it has an incredible suspension for a pack of it's size and weight, however the down side for me is the poor cut and location of the shoulder straps, and the cut of the hipbelt. However, I'm probably not getting rid of my Circuit anytime soon because it's 'good enough' and carries very, very well. The Crown is a better designed pack from a better pack company, no disrespect to ULA, but it's clear when you put the two side by side you can see and feel the differences, this comes out in things like compression design, hipbelt cuts and cants, shoulder strap placement, width and cant. So, probably the best way of saying this is that if the Crown had an actual suspension system outside of a stiffened framesheet, it would hands down be a better all around pack, however, that's a pretty big difference in my experience and considering that the Circuit is basically the same weight AND offers superior load transfer capabilities, it would be hard to pick a clear winner. In the end I would base it on how each pack feels on your back and your personal preferences, however regardless of your personal preferences, no pack with ONLY a framesheet will ever be able to carry as well as one with a proper suspension, so like I said earlier, if you're on the wrong side of 12kg (25lbs), consider something with a good frame, if you're a little lighter, you might not need it.
If I had to pick only one? Not sure, can't answer that today with confidence, however considering my pack is normally around 9-11kg with food and water for a typical trip, I would probably choose the Crown because I just 'like' the pack better, it feels better on my back, and I don't see the NEED to sacrifice fit for suspension with 9-11kg loads. Finally, packs are very much like shoes - they tend to pick us more than we pick them - so feel is everything (but remember ignorance is bliss). Try them on loaded with weight and wear them for a while, that's the only way to get a accurate picture of each.
I hope this helps