Hello guys, big SC2 fan and have it played since its release (Collector's Edition) so I have never experienced any mouse trouble, at first I used to play with my Magic Mouse but then I switched to a Razer Spectre (and Razer Banshee) and has worked well. With the Razer Spectre there's this know issue with the Phillips track sensor but never experienced as well, now both of my Razer devices are 1 year old.
As to my multiplayer performance I started in Bronze League (Season 1) and have been promoted to Platium and also demoted to Silver lol.
I started playing SC2 on a Early 2008 17" MBP on Low graphics settings, then I got a Early 2011 17" MBP on high settings, the game was fast but it took forever to load on multiplayer. Now I play on a Early 2012 15" rMBP and its beatiful, this beast can run it on Extreme or Insane settings with no problem.
It's good to see that the SC2 mac community is growing, hope see you guys on a match soon!
P.D. Sorry for my english I'm mexican so...
----------
Heart of the Swarm. It's the expansion of the game that's currently in beta, set to come out sometime next year.
Lol 4 days after your post the release date was announced, March 13