Late-2008 15" MBP: 2.53GHz vs. 2.8GHz? Worth the extra $250 for just the extra CPU speed, when both have 320GB hard drives, 4GB DDR3 ram, and 512MB 9600M GT? $1449 vs $1699. Opinion? I use Photoshop CS4, record videos in AVI format and compile/encode them into DVD format, FileMaker 10 Pro Advanced, various Virtual Machines, videos, light gaming, etc... Starting a graduate program in Computer Science this Fall, so probably some programming too.