I've been using a low voltage 125-1250 kernel. I get great battery life, too. It's usually 24-30 hours between needing a charge.
I think it might have something to do with the fact that my phone is actually a CDMA Milestone, which is supposed to be identical to a Droid 1, but I'm guessing the hardware is a little newer and/or better. The thing can be overclocked like crazy, and runs very stable and cool.