Just made the switch from my Sprint Treo 650 to the TMO 8700g.
So far so good, despite the fact that I cannot see my contacts that i add to my address book.
I recently made the switch from Treo to BB myself and I must say, I am quite happy! I had a Treo 300, 600, 650 and a 700w. I recently switched to the BB and I'm not looking back!