I currently have a 2009 iMac 21.5" still running Snow Leopard. It's the entry level model. I can't even edit HD 1080 and I do a lot of editing now. I really want the top of the line 27 iMac, but with the fall coming this is usually when they release a new model. Should I buy now or wait a few months? I truly need to get one by the Fall of 2016. Are the current iMacs capable of editing in 1080 without getting glitchy? Or is it recommended I wait for the newer ones?