Newbie Question

[timm9]

Please excuse the newbie question. I have searched but did not see any posts that specifically answer my question.

I have a HTC 6800 running Win Mobile 6.0 with a small (CDMA) carrier in the Sierras. Due to the size of the carrier, there is no ‘upgrade’ path to an official ROM, nor does the carrier have access to the original ROM currently installed on the phone.

While this small carrier provides excellent service, their customers do not have the ability to receive data while roaming and will not have this feature for quite a few months to come, which I desperately need for business. I’m considering switching to Sprint and my questions is this; If I upgrade to Sprint’s official ROM and later wish to return (after they have data roaming) to my current carrier, will a hard rest on the 6800 remove the Sprint ROM, or will the 6800 be forever branded with Sprint? Should I just buy a used Sprint smart phone instead?

Thanks!