Agreed. I would call Apple's Magic Mouse the worst mouse of all time if it didn't have the cool feature of working as both a trackpad and a mouse. Haven't really seen that elsewhere
It doesn't matter that there's a trackpad on the top, because you can't use it. You'll need to curl your fingers to an uncomfortable degree and there's to little traction beneath the mouse to prevent it from slipping when using the trackpad functionality.
My guess is that the Magic Mouse needs to be close to 50% larger, certainly taller.
The Magic Trackpad however... I hope they never stop making those. That is the best input device anyone ever made. It's large, stable, precise and just a joy to use.
The Sun optical mice managed to be both annoying and clever - they didn't get too dirty but the effect was often the same, skipping around when they should have been smooth.
I was a fan of the Logitech TrackMan marble. (I preferred the one with the thumb wheel).