I just got my pearl, upgrade from a 7100t, and i have to say that I love it! It looks like some people have been talking about switching from the tmo os to the o2. is there any advantage to this or anything? thanks!

fixes a few annoying things. Most noted is the ringer muting in pocket or with slightst touch of trackball.

That was the big one for me, search and you'll find some pretty lenghty threads.