I just bought a refurb Alu iMac, just the base 20" to tide me over until Montevina MBP's hit. This will be my first Mac. The PC I'm currently using has the following specs: Pentium 820D Smithfield @ 2.8Ghz 1GB RAM ATi Radeon 9250. How much of a boost am I looking at in performance, when it comes to games? I realize that the HD2400Pro isn't anything special by any means, but I'm guessing it's going to be leaps and bounds better than my 9250?