I have a Verizon Touch Pro on CricKet. It works fairly well with the exception of the special Verizon crippling of the RAM and such which problems would still be there regardless of carrier.
When I want to update my PRL over the air I go into the EPST settings and update it with the 1042 PRL (attached). I do a *228 after it restarts and CricKet updates me with the newest PRL. This is the way for me to update because of not having a supported CricKet phone.
As far as ROM's go I've had the best luck with Calkulin's 6.5 Kitchens. They seem to be the most trouble free and have given me the best results. For my MMS I just use the cab in this thread that has been a serious frustration reliever:
http://forum.ppcgeeks.com/showthread...ricket+arcsoft
Follow these instructions on setting up your EPST settings and you should have an awesome working phone:
http://forum.xda-developers.com/showthread.php?t=492824
Everytime you flash a new/different cook's rom make sure you check your settings because occasionally I've had a couple of areas revert to
xxxxxxxx@xxxvzw.com. Haven't notice some of the other settings to be a problem.
These solutions have worked so far to solve these area's of concern. I've never messed with a Sprint Touch Pro to see what other issues can arise.
I'm pretty sure you can put on these settings and roms on the Diamond and be just fine. Ask around if you have any other questions.