I'm playing with USS and I really love it.
For me it has given by far the best hit and feel from the low-squirt shafts. It has more squirt than Predator, but then again much more feel, and the squirt is not too bad either, as I used to play with stiff custom which had squirt A LOT..
I'd say USS is a Golden Middle Way between the custom shafts which has lots of feel, and between Predator which has less squirt but not enough feel.
The biggest problem with USS is the quality. There has been some problems especially with the ferrules. They do have warranty, but you need patience unless you get lucky on the first try.
I have now two good USS shafts, but I had to return 2 or 3 until I found these.
I'm playing with 12.75mm, and I have no reasons to look for other shafts, as I don't like Predator or OB-1, and the Custom shafts just have too much squirt and for example shooting inside english becomes so much more difficult with them.
Only interest what I have, is to try the 11.75mm version for some time. I did try it for a half an hour or so, and it felt great, but I'm not sure which would be better one..