I've used this app for about 2 weeks, and while it did some cool things, it'd never retain ANY setting after a reboot. CPU was always back down to 1000k from the 1500 I had it at before, SD read speed was at 128k vs the 2048 I preferred. I've had two different versions, one that came w/ my currently Legendary RC 2.2 ROM, then another I downloaded from Mobilism. Neither version retained anything after a reboot. Today I tried downloading it from the Market and it says that it's not compatible w/ the Epic and wouldn't even allow me to download it. Great app, but if I have to refresh the settings everytime, I may as well stick with SetCPU and flash an SD speed.zip to retain my settings.
Epic 4G - The People's ROM 2.21 FC09 MTD running GB 2.3.6 @ 1.5Ghz w/ baked-in Samurai kernal, LauncherProPlus 0.8.6