In my case, the battery drain issues were not because of the ROM, I get it with other ROMs as well. What I've found is that it is usually because some process couldn't connect, and it keeps trying, generally ActiveSync. Here's some links on how to kill it:
http://www.mobiletopsoft.com/board/1...r-battery.html
http://forum.ppcgeeks.com/showthread.php?t=35647
http://forum.xda-developers.com/show...3&postcount=81
Some combination of all of those stopped the drain (as well as the overheating) for me, most of the time. The other times I found it was because some process was loading at start-up (VZo Mobile for me).
A task manager with process display is useful for diagnosing these issues.