The CM kernel is broken, apparently, and as that's what's being used here, we get the same battery life or lack thereof. Apparently there's broken GPU code that has been fixed in other kernels such as Doomlord's, but that the FXP team won't fix in CM. Edit: Riyal knows the details, am just repeating what someone more knowledgeable than I said.
I have to say that while I have enormous respect and appreciation for any devs who give up their time to make ROMs for free for the rest of us, the FXP team are probably the least responsive CM group I've seen on any device I own. I find myself refusing to entertain ROMs with a CM base on my Pro, because I know the battery life won't get me through a day. Avoiding CM is unheard of on my other devices.
but hey, for those of us without the wherewithal to create our own ROMs, opinions are all we have to contribute, and they're like arseholes - everyone has one. Yours may be different to mine
Don't suppose the TeamX guys fancy having a crack at their own kernel, do they?