If you're really careful about your compositions, you're less likely to have to crop an image to retouch a stray element in a photo if you're using a 100% viewfinder. It's definitely my preference to see the exact image I'm taking and not less than that, but I don't consider 95% to be a big problem. It certainly wouldn't hold me back from using or buying a D700. Heck, I own Leica M6 and M7 rangefinder cameras, and the viewfinders in those are wildly inaccurate compared with most SLRs. Somehow, I manage to get by. We obsess about some of this stuff too much.