Need help with unlocked phone

I am thinking about buying a unlocked Nokia 6800 which is a qwerty keyboard texting phone. I already have verizon and will be replacing one of my phone now with it. Is buying a unlocked phone and easy process to get it to work? It needs to be able to text. I heard getting some features to work on a unlocked phone is sometimes difficult or impossibe. Could somebody please help me out and shed some light on this. Thanks