Though I have somewhat smallish hands, I am used to big frame cameras like all of my film cameras so the D700 has a good, natural feel to me. I did get the MB-D10 for it as it gave the D700 a very similar feel and heft to my F2 w/ the motor and F4S and gave me more battery power and time before recharge. The camera is built very well and now that it is an "antique" you can get the MB-D10 for a reasonable price, not the $300+ I spent for mine. DON'T waste your money on the cheap, plastic knock-offs!
And don't think for one minute that that "paltry" 12.3MP is a handicap. It is not, not by a long shot. The D700 does very well in low light and higher ISO's. And for prints up to, and perhaps slightly larger than, 16x20" its image quality is outstanding. The glass you have mounted and your technique will be the limiting factors, not the camera. I have had several ad images I took wind up as billboards and they look terrific. And 94% vs. 100% finder coverage? Who cares? Only if you never crop your images. Who does that, not me.