Any disadvantages to the 2TB + SSD that I should be aware of? Since it is difficult to replace hard drives, I figured I might as well get the larger hard drive. I hesitated at first, though, because I already have a 1TB portable hard drive. Is 2TB overkill? Also, as the thread title already asks, is there any truth to the claim that the 2TB HD in the 2011 iMacs is noisy?