If you really want to see a noticeable increase in battery life, a Gingerbread Sense-based ROM is probably not where you're gonna find it...Some ROMs may be better than others, but I wouldn't expect any drastic improvements until at the very least the kernel source is made available.
I was getting better battery life with BAMF 1.8.6 (Froyo), but I've been using this version too long to go back now.
I personally like Sense 3.0 enough to deal with the battery life, but I do hear folks claiming to get much better battery life with some of the AOSP and non-Sense ROMs.
Got ya, its almost a bad thing I experienced this then, because I dont think I would change from it either haha. Great ROM and I have not run into any problems, only slight annoyances of preference.