Not that I'm aware of. I've used both the VM 4 and the VM C. Some weight and fit and finish would be nice. The C certainly feels nicer than the 4. I keep trying other things but eventually gravitating back to this.
The 3M joystick mouse might be worth a try, I have tried a model of mouse similar to yours and found that I much preferred the joystick mouse due to being able to rest the side of my hand on the base. With the mouse that was similar to yours it seemed less restful. Maybe worth a try if you haven't tried it. I keep on trying different mice and always come back to the 3M joystick mouse. It certainly isn't perfect, and I miss the Magic Trackpad gestures terribly.