I realize the implementation of U1/U2 may not be perfect/adequate/sufficient to all needs and users. To those, just ignore them the way so many snobly ignore Scene, Auto and P modes. But having these is much better than having nothing.
To other users, U1/U2 are just great.
On my D7000, I used U1 as a "strobist" set, manual exposure mode, Fn button to recall flash commander modes, other small details. U2 was set also for manual mode, but with AutoISO enabled, thus making it a mode much like A or S, where you have two control wheels setting two sides of the exposure triangle, and the camera adjusting the third parameter. This one was quite usefull for tele work under difficult lighting.
As soon as I got my D600, in a couple of minutes I had all my favorite settings dialed in as in the D7000.
As a disclaimer, I have never shot a camera with Custom Banks. If I had, perhaps my opinion would be different. I'm just saying that, although I acknowledge the limitations of U1/U2, they are still very helpfull for some people.
http://egozarolho.blogspot.com 1. Good content, good aesthetics and good tecnique. On that order. 2. Light is more important than glass and pixels. 3. In the digital photography process, software is as important as gear.