Logitech V470 is worth checking out. I previously was considering replacing my Magic Mouse with a conventional bluetooth mouse. 470 gets some good reviews and comparisons with the MM, but I haven't tried it yet. Available from Apple store and other places.
I use an older modified Logitech wired mouse as an occasional alternative to the MM. I hate the "click" that happens when a conventional mouse wheel is rotated so I removed the mechanism (just a couple of tiny parts) so the wheel rotates smoothly. Lots of mice now have smooth-rolling wheels.
The MM can be improved a bit by using a low-friction mouse pad and using smoother feet or tape on the standard feet on the bottom of the MM, to reduce the friction that makes it clumsy for small movements. But it's still too low and small, I think they put too much emphasis on form over function, it looks beautiful but for many people the Magic Mouse is painful to use for extended periods.