Colin, I agree, the grip adds to the attention factor of the camera (throw on an SB910 and it REALLY gets noticed).
I like having it on and off...for when I decide to go incognito or when I plan on shooting more vertical images. I do love the battery life of the D700 and EN-EL3e. Took the camera on vacation and it lasted very well. Did pretty good at an air show, too, 1000 RAW images on a 16MB card...with lots of chimping and still had some power.