i have the 8801 in silver (unbranded, not the tmobile version), and its really not a very good phone, terrible battery life and it really is a very basic phone. I would avoid the 8800 sirocco, it still lacks the 850 band. Plusses it has a better screen, bigger battery, and the place where you flip out the screen is easier to use now.
I really only use it as a going out phone b/c I don't feel like carrying my blackjack around. Seriously it sits on my desk in the charger until friday night rolls around.