I finally took the custom ROM plunge... been running Nils' Business Gingersense 3.0 for about 24 hours now.
I've had my Incredible since day 0 (one day prerelease) and it's been rooted as long as root has been available, but other than using ejhart's HydraKernels I've always stuck to running the stock ROMs (Eclair which came with it, then Froyo when it became available last fall). I'm no stranger to custom ROMs, used to cook them myself back in the days of my HTC 6800 and Touch Pro, but never with Android till now.
Obviously, I've only had a day to play with it, but Nils' Business Gingersense 3.0 is fabulous so far. All the good stuff, none of the bad stuff. I haven't noticed a single issue with it... battery life seems to project to be about the same as my stock Froyo with a custom undervolted kernel (about 36 hours) which has been my concern with any ROM I considered.
Admittedly, I'm a lighter user than many, so consider this a comparison to stock rather than a "you'll get fantastic battery life!" sort of thing. I'd say it's equal to or slightly better than stock Froyo. YMMV.
Oh, and it's pretty snappy, too. Glad I finally took the plunge.