i'm on my EVO since my pre got hit by salt water. I have to say, I'm probably the only one that misses Web OS. I think mainly, I use multi tasking quite a bit. I'd say battery life is about the same, but I never have a problem. I have a car charger, and whenever it's in the car, it's charging. Same goes with the EVO.
However, it wasn't until recently, where I sided with the EVO. That's only because I rooted the damn thing, and installed CM6. Wow, what a difference the 30 fps did! I almost went back to another Palm Pre!