I've had my 2010 13" Ultimate for 3 weeks, and I must say I'm disappointed with the CPU power after testing it with DAW works. Coming from windows, OSX eats much more CPU power even just for light task. Some very basic task would have used just 3~4% of CPU under windows but in Mac it took away as much as 15% with similar setup and tasks.
Other than that, every bit about is has been positive. I'm a touch typist so backlit keyboard is just eye candy but that said, having backlit keyboard always make you feel like you're using premium product, especially when they manage to stick the backlit into such a slim machine.
Anyway, in the end, I decided to give Apple a call to try my luck if I can return mine for the new one simply due to the inefficiency of handling audio related tasks. I can definitely keep the 2010 if I failed to exchange for the new one though.
PS: I also tested the battery life after installed Coolbook. I was under the impression that it gives battery life as long as 9 hours. But after doing proper test, I find that with just light browsing without flash (browsing/replying forum without much pictures attached), it can manage upward until 8 hours - very impressive, but certainly not too much of an increase compared to the latest MBA. Yes, 1 hour is big deal, but I start to play around with some tasks that required more CPU juice which is closer to how I'd use the machine, the battery life just dropped significantly (8 hours versus 5:30~6 hours). Seeing how owner reporting that similar task showing similar battery life (medium-light tasks) as my "Coolbooked" C2D, I finally convinced that going for the new one is a wiser choice, especially when I know I have so much more power at disposal when plugged in for DAW works. 🙂