Lorenzo,

I get between 400 and 500 shots out of one battery, depending on how much I chimp. IS drops that down considerably, but that's not something you use often anyway.

THe battery life is much less than my D100, I could get 700-1000+ images on one battery with moderate chimping.

For portrait work, I can't live without the grip. Actually, for pretty much any vertical work I find it necessary. Cool thing about the BG-ED3 (Big Ed) is that the buttons on the vertical grip match the ones on the body, so you can use them in preview modes just like you would the ones on the body. Makes for less shifting of the camera when previewing images.