If i upgrade to the 4.5 software from my tmobile 4.2 software can i still use all the features that i have with 4.2. also will hrt work right

I upgraded ages ago and never looked back . . . well worth it . . . what feature(s) are you particularly worried about? I can check if it's still on mine

Here is my advice: If your BB does what you need and want it to do, then it isn't broken and doesn't need to be fixed.

Why risk screwing it up unless there is some feature or bug fix that you really, really need?

all i am worried is the im and mms features i have on my plan. i updated and it is better. also my HRT