I got a BB curve that is AT&T and unlocked for tmobile, it appears NOTHING is missing.

Now if i get a bold that is unlocked will everything work? Including the 3g? I only can find 2 year posts that claim NO.
But nothing recent....
After seeing a thousand different answers it appears that the 3g network for tmobile in USA uses 2100/1700 freq while the bold uses 2100/1900/850 MHz

Since tmo uses both freq, one for upstream and one for downstream, that means no 3g? For bold or Tour with tmo?

Just want to get some other people to point out any mistakes in my thinking.