For the extras required to make your 7730's BT capable its not worth it. By the looks of it there will be a forth coming update to the TMo line of product the 7100 is rumoured to be one, not sure when? Although very phone centric I would recommend the BB 7290 (yes it has BT and offered by TMo) Traditional keypad like the 7730's and more of a work horse in comparison to the 7100 series.
http://www.blackberry.com/compare/co...eView&x=22&y=3