Stay up to date with the latest ROMs. As long as you are on the current Software release provided in a custom ROM you will be ok. Otherwise, it will be up to the developer to disable the OTA in the ROM if you are on an older build.
Right now I'm using the stock ROM, as I literally just got the phone last night. I installed adwlauncher and use that now instead. I am used to using CM7 with my old Hero, but not sure which ROMs are good for this phone.