Literally just about to click the buy button when the question set in - Will I notice a difference? I am a professional designer and work on large documents and files that drain my iMac and I sit there waiting for it to complete its task. This time wasted = lost revenue. I currently work on a 20" iMac Intel Core Duo 2GHz with 2GB memory which has served me well but needs replacing. The iMac I was going to purchase is the 27" 2.7GHz Quad-Core Intel Core i5, but WILL I NOTICE A DIFFERENCE? or will I still be sat there waiting for it to complete large tasks? Any help greatly appreciated, thanks.