I've been running No2Chem's clock tool for a few months. Earlier versions were a bit buggy for me, but ever since 1.3 it's been flawless. I've probably flashed through 15-20 ROM's in the past couple weeks and used version 1.3 of the clock tool on every one without problems. I work in a low-signal area which kills the battery quick as we all know. I never use EVDO, 1X only all the time to help battery life. I used to use the clock tool to downclock to 384MHz all the time and 19.2MHz when in suspend mode. Now I leave the cpu at 528 and go to 19.2 in suspend. Without the clock tool I can't get through a work day on one charge. With it I have 30-40% battery left at 5:30pm.
Only way to find out if it works for you is to try it. You can always uninstall.
