My battery life has always been REALLY good with VaelPak. Also from my personal experience as well as hearing from other people, VaelPak may very well be the most stable ROM you can use, especially when it comes to the NonSense roms. I hate to admit it, but so far VaelPak with Kings BFS8 has given me not only the best performance, but also battery life with NO compromise between them. But, I'm on a hardcore boycott of anything from Kings. I've been using Netarchy since and so far it's been really good. Not as fast as Kings 8, and battery isn't as good as Kings 8, but it's still better than any other kernel I've tried. With all this said... You still have to test and try yourself. I still don't understand it but Evo's can vary almost on an extreme level. It's really weird. But I'd say the majority would have the best battery and performance combo with the ketarchy kernel. As far as ROMs, I'm VaelPak 100%. But that's just my opinion. =D