Nice choice! I have one myself
Never owned a Mac before (PC user for 15+ years as well as working on and with PCs all day) and now it's my main machine! OS X is a brilliant OS IMHO - but there are a lot of things that you have to "unlearn" if you're switching from a windows system.
I reckon the biggest single factor in computing performance is the user
The computer is just a tool. YOU don't have to be one as well! (sorry, just been caught up in too many Macs vs PCs debates lately.)