You'll find some useful information in some of the existing threads on this topic:I have the june 2012 MBP is it worth it to buy the magic mouse or tracpad?
I have the june 2012 MBP is it worth it to buy the magic mouse or tracpad?
This.If I were you, I'd buy the mouse... because you already have the trackpad...
a trackpad when I am running in clamshell with an external monitor. I think it gives me the best of both worlds and it isn't really that expensive.
I have the june 2012 MBP is it worth it to buy the magic mouse or tracpad?
If you use an external keyboard, yes. Moving your hand to the trackpad when it is behind your external keyboard is awkward.
I got the trackpad.
Apple's mice are pretty crappy, imho.