Mike, please read my posts, and see my scenario. Look at the rates you get. Each has it's benifits.
I think Boost would be best for me, because I get a good rates and extras, even if I use it a few times a month. Won't cost me ~$20 extra per month.
Do you know Mak, if Boost has a minimum of how much you have to pay every 90 days? I know virgin's minimum is $20, ATT is $25, etc.