I want to say nextel is weak, but i have yet to run into any problems *knocks on wood* with sprint. I dont believe they use the same everything just yet. I have heard from many that you need to keep an eye on your bill because sprint was known for wierd charges, yes they would always fix it. But it would still suck to deal with. I was under a company phone for some time now and didnt need to look at the bill. But for the last 4 months everything seems to be fine.