Trouble is with Mac you have no option but to buy an external device if you fancy trying surround sound. Once priced up the Intel Mac Pro due to the "Best for Photography" Myth. Fair enough you can spec them up very well, 32GB ram, loads of hard drives, 4 graphics cards etc. What stopped me in my tracks was the fact I'd then have to spend out on an external component to listen to music through 5.1 dolby.
And another thing was I could get a 64bit PC for 4 grand cheaper!
Macs are very nice to use, but still (only in my opinion) not as versatile as Windows based PC's