I've been a Sprint customer for almost seven years and have typically bought my cell phones from a Sprint store. I've got my 18 month $150 phone upgrade voucher in my hot little hand and I'm seriously considering the new 650 (would be my 1st smartphone). With issues that the Treo 600 faced related to bugs and potential for returns due to malfunctions, with which type of store am I best protected?

Best Buy - for their warranty coverage of the phone as a PDA?
Sprint Store - they'll be most updated about the 650's potential operating quirks?
3rd party reseller (Radio Shack, etc.) - not sure if there's any advantage with them, but I thought I had to put them on the list?

Any advantages of one store over another?

Any advice from those who've lived with returning their 600s over the past year to get one that works would be most appreciated.