I'm the same way, I don't like camera straps. The MD-1/2 provides more grip than the camera alone, but its square shape doesn't lend itself to a comfortable grip. It's also heavy. In order to save weight, I've tried using my MD-1 without the battery pack, but I didn't like it. I found I'd grown used to resting my pinky on the battery pack and without it, my finger rested on the hard edge (also, the motordrive obviously doesn't work without batteries, and I use the MR-2 secondary release a lot). I want to try an MD-3; its round shape reminds me of the MD-12, which is extremely comfortable and provides superior grip. The MD-3 doesn't have a rewind feature though, which is something I would miss.
Originally Posted by GarageBoy
The MD-4 is a nice shape, but it gets really slippery since the grip is just painted metal without much texture.