so the thoughts:
- no visual changes (maybe just in properiences in "my computer" :) )
- no performance improvements (hard to test in virtual machine environment, but in a few days I'll test it at some laptop or PC and make a comment)
- instalation is rather simple, and with no complications only one reboot is needed (it is a 3 times better than vista SP1 )
- I'm going to test NAP, because it is the most interesting thing which was implemented in SP3...
so... see you in the future :)