I'm using the most current Sprint Raphael radio and find it gets rid of the heat issue and brings better overall stability. Version is 1.11.00F You can find it here:
http://forum.ppcgeeks.com/showthread.php?t=46616
Those downloads shouldn't perform a hard-reset either, so you're good to try them out; just be careful.
Someone did an actual scientific test to see which radio was the best overall and I think they found a split between one of the Telus ones and the Sprint 1.11.00F radio.