None of the above? IMAO, 3rd part mouse > magic mouse >> magic trackpad.
The trackpad always seems I can't get the accuracy I want or the traversal speed. Most of my experience is on my rMBP15", though I have played with a coworkers magic trackpad when helping with his computer, and it generally frustrates me just as much.
I really like the scrolling support on the magic mouse, but the resolution just seems too dang low, especially when using 4k or multiple 27" displays -- haven't found a preferences setting I've been happy with. So most of the time I use a bluetooth or wired mouse -- the HP X4000b has been my favorite bluetooth mouse.
Another part of the problem is I really need a third button for work (X11), and while option-click works on the magic mouse, a real third button is more convenient. Trying to map the middle of the magic mouse to middle button just isn't reliable enough for me. So maybe I haven't given the magic mouse a fair enough shake.
I've also loaned one of my spare magic mouse to various coworkers, and it always comes back in a few days, so i'm not the only picky one. 🙂