Having recently made some backpacks, one somewhat but not totally modeled on parts of the ohm, it's worth noting a few things re your comments as OP. I have no personal interest in ULA packs, either way, positive or negative, though I have studied their designs to get some ideas. It is good to re-examine companies however, particularly after key people involved have left them, that is a fact.
1. If you are putting enough stuff into the pack to make the rolltop uncloseable, you bought the wrong size pack, period. The last roughly 1.5 or 2 inches of the rolltop should in no case be considered as 'extra space', it's the closing mechanism. I don't know what ula uses since I've never seen one, but when I decide how tall to make the rolltop part of the pack, I figure it this way: with a pack body thickness of 6", the top needs 3" to close, then x inches will form the actual height of the rolltop extension. I use 1/2 hem on the top of the rolltop, so I roll it in 1/2" intervals, roughly, and consider 3 rolls or so to be a nice safe closing, so that's about 2". Say you have 6" extension, plus 3" to close it back to front, and 2", that's 11" total, but that doesn't mean you have an 11" extension, it means you have a 6". the last 5 inches don't count as height. So you have to take that into account when you get the size you need. ULA cannot be criticized for this in my opinion, it looks like you simply bought the wrong size or have too much stuff for this type of pack, or something.
2. As Peter stated, accurately, stays should not be prebent if it's a form fitting bend, because the person has to do that bending. I had lowe alpine internal frame packs that came with clear directions on how to do the bends, since they were bomber, you didn't need to do the fine tuning Peter talks about, you just bent them to your back, the aluminum stays were very thick, and held it under weight. I'm sure lighter packs use lighter stays, and so you have to be more careful when adjusting them. ULA is to be commended for not prebending, not criticized, if you prebend, then you have to unbend, then bend again, not good. So that's not a real issue.
3. When you compare packs, you must compare them by weight, you cannot compare some REI pack that weighs maybe 1 pound more to another ULA or any other pack that weighs x ounces less, it has to be apples to apples. So it's useless to say, oh, this osprey/deuter/northface pack does x or y and a ula does a or b, you can do stuff when you get more weight in that you can't do with less weight, so make sure to compare only apples to apples.
4. Specific to older ULA packs, that highly slanted pocket, very shallow in front, what were they thinking? That to me was a major error, but they fixed it.
5. Re front pocket depth: I don't know what true depth ULA packs have, but I made my first pack with a 2" depth, and regretted it immediately, so I made my most recent one with 3.5" depth, and that was awesome, perfect, enough to hold stuff. I don't like elastic mesh at all, I prefer the solid mesh, with about 1/8" holes, so I won't say more, but elastic wears out, and solid non elastic does not.
6. Re side pockets, when comparing packs, what capacity does a pocket have, ie, can you fit 2 quart bottles (I just missed that on my measurements, so it only holes two narrow quarts, not two standard sized). Most commercial packs seem to have relatively small side pockets, a big side pocket doesn't 'look sleek and well designed', because it is actually big enough to hold 2 quarts, or close to that.
7. Re feeling like a board, if there is no extra padding on the pack, which is likely if it's a light or UL pack, then that is a fact, but I had no difficulty with this type of system, I believe my main pack is similar to an ohm, ie, side carbon fiber tubes to prevent body collapse, a delrin connection between top of tubes across pack to support the shoulder straps. I agree on the weight distribution you note, I can't get much better than about 50-60% onto my hips, but at max 25 pounds, that's fine. I use wide shoulder straps, it's not an issue, I didn't feel the pack on its first trip, and it didn't bug me, so I would say that type of experience suggests it works. I use a thin 1/8" pad as a back/frame as well, it's in a pocket, inside the pack. I'm unclear on any real benefit from carrying it against your back outside since I don't see how that would stiffen anything.
With this said, some time ago, I bought the last real pack that Lowe Alpine made, prior to their getting bought out, sad, the Zepton Hyperlight series, excellent pack, 'well designed', has features no cottage type gear maker can ever achieve because these big companies can source specific parts in large volumes from suppliers nobody else has access to from what I can see. Very good 'design', in terms of looks. Excellent weight for what it was, also had a very good curved steel stay that is VERY strong, but very light, pack weight without top is 2 pounds.
Seams: not so great, not bad, but mine are better, I've seen consistent unraveling of them but I don't use the pack anymore so I can't tell you how long they would last, I'd guess about 45 to 60 days max before you started getting structural failures, but it looks nice, good design. I would bet ULA's stitching is quite good if you look at the actual construction, when you care you can do more stitching, that's just how it goes. As Mchale has noted, he 'uses a lot of thread', which if you start sewing your own packs starts taking on real meaning, using a lot of thread means taking a lot of sewing time, far more than you would expect most commerical corporate stuff to do. The Zepton had no real side pockets, just these annoying flat elastic things that you can barely squeeze a quart, if that, into. No adjustments possible, ie, it's elastic topped, so when that goes, your pocket is gone. No front pocket at all, that's a major annoyance. Excellent, and I mean really excellent, suspension, because they have access to tooling and components that nobody in the cottage gear sector has, but even with that, a lot of oversights, no daisy chains, no hip belt clips to attach stuff, and I am suspicious of the durability of the shoulder strap connections. The sternum strap elastic basically died after 1 trip, or died since then from sitting in my closet, I don't know which it was. Doubled heavy duty elastic fixes this. Because most of the 'corporate' packs now use the custom made sternum strap sliders, when you lose functionality it's either hard or impossible to fix the strap, with a more 'home made' style, you just take it off and resew it, it takes about 5 minutes.
I wouldn't be so quick to assume that just because they (the corporate stuff you see at REI) have nice curves on their cuts and a few other things that these commercial packs are all that great, it's a case by case basis, who is sewing it, how stressed are they for time, how are the materials actually handled, ie, are they compromising pack body/features for minimizing nylon wastage?
With carbon stays, however, it's kind of obvious that the problem is that cottage people simply cannot charge what it would cost to have custom made carbon fiber frames made, so they have to use standard materials, like carbon tubes, aluminum slats, or aluminum tubing. Tubing, by the way, is very hard to bend.