i saw the Mac pro *used for about the same price of the retina macbook pro 13 inch. The mac pro was released in 2008, but what ive heard is that old Mac Pros cant have Mountain Lion. i mean i dont get it, im not computer savvy but as far as i know the more the cores the better? i5 dual core vs 2.26ghz intel xeon 8 cores? which one would you go for? im confused portability is not a factor for me. i just like to use for entertainment, photoshop editing and plan on using imovie a lot. please correct me if im wrong.