I don't have both watches (only a UTS), but here's what i found when I compared them side by side while at a dealer while on business in Vienna last year:
1. First, I am not sure of the exact measurements but the U1 had definitely a slimmer and sleeker lines to my eye than the UTS. The UTS is much more blocky.
2. To my eye, the U1 looks really good on the black rubber strap but loses something on the bracelet.
3. The U1 looks like every inch the tool watch. The UTS has more of an 'industrial design' look. In the sense, I could see the watch having been made by someone who has designing experience in one area and has decided to apply this to watches (which actually is the situation).
4. The case of the U1 is really beautiful. Matte, beautifully crafted, and somehow feels different to the touch than the regular 316L steel. It's the killer app for that watch
5. Part of the pleasure of owning a UTS is that you look at the watch and think this is really the work of one guy. It doesn't necessarily mean the watch is better than one that is produced by 10 guys (Sinn) or a 100 guys (Rolex) but it does lend a certain 'je ne sais quoi' to it that either you appreciate or are indifferent to. if it matters to you a lot, you will cherish a UTS beyond its actual physical attributes.
8. As I said, I find the killer "app" for the U1 was the fantastic case. The crystal, dial, bezel action etc seemed more standard though still of high quality. The UTS seems like every component the bezel, case, crown, case back, bracelet is built with equal care and consideration. I would not say anything stands out singularly as in the U1's case.