I've run a good number of DX roms, liking some more than others, and disliking some that imbed themselves in your system making it harder to remove. I think at best among the various roms, I got up to 28 hour but right now I don't recall which of those roms it was. Anyway, I went the sbf/factory reset route to start from a clean slate. Similar to jellybean420, I'm running stock odexed de-bloated (freezing unwanted apps via Titanium), then used QuickOverclock to determine my lowest voltage range and set underclock to 300-900.
What caught my attention was how zippy and responsive my set-up was working AND the battery life was seeming to go on forever. Well, no, that forever, but with moderate usage, at 51 hours I still was at 30% on my battery. I could probably go 60 hours at that rate. I'm not using any battery saving techniques other than the built-in Battery Manager, along with Timeriffic...a free app on the Market that works great to let YOU schedule exactly when you might want to turn off wifi, put your phone into airplane mode, turn off sound, etc. etc. and then turn them back on (such as 10p-6a, or during classes, at work, on which days, or whatever).
So, I'm not motivated to re-load a custom rom that's guaranteed to both slow me down and drain my battery 2 to 3 times faster than what I'm getting now. Of course, YMMV.
