Lippsman, question for you

Not sure if you have had any experience with unlocking an iphone but i thought i would ask. Do you know if they work the same once you do it? I have tmobile now and am thinking of getting one and just wanted to ask if you have heard anything bad about unlocking one. Thanks

what kinda software doesnt work? I really only want it for the internet so does that not work? And i heard as long as you dont upgrade to the new firmware that it should work fine. Is that true? Thanks again