I'm using an early 2009 24" iMac at the moment. It's my general PC for everyday use, but as a keen photographer I'm now spending a lot of time in Aperture and Photoshop. Whilst my iMac is noticeably slow at times with these photo programs, and I'm ready to upgrade, I don't know whether a new iMac is going to give me much more performance, or whether these programs justify giving a current (or even recon) Mac Pro some consideration? I don't want to pay silly money for something that will only give incremental benefits, but I would like things to be a bit whizzier. If I go the Mac Pro route, what spec do I need to give an appreciable benefit over a top line iMac on photo work ? I don't handle video at all.