My BlackBerry 9930 on Sprint was the finest BlackBerry I've ever owned. I consider it RIM's high watermark in hardware. I still have my 9930 in a charging desktop cradle in case I want to jump back to BlackBerry. I also have my BB 9650 ready to rock. I like to keep my options open.
The reps at the Sprint store are dopes. Either of these two models will give you years of great use.