The MD-2 has a plastic gear that loves to self-destruct. Get an MD-1 or consult Sover Wong for an easy fix for the MD-2. I have an MD-1; it's damned heavy but I can't imagine life without it, mostly because I like having a hand grip (I don't use a camera strap; my camera needs to be in my hand, ready to go, or else it doesn't get used).
If you can get a battery pack with the AA holders, lithium batteries work great. They make the camera top-heavy though.