Thinking about a refurb 20" iMac. Is there any significant hardware bug fixes between the 20" Rev C and Rev D as described here: http://guides.macrumors.com/Intel_iMac I definitely want the ATI Radeon HD 2600 PRO card. Right now I can get the Rev C 20" for $1049. The Rev D is $1299. For that $250 it looks like all I get is: - 2.66 GHz vs. 2.40 GHz - 1066 MHz FSB vs. 800 MHz FSB - 2 GB instead of 1 GB RAM (doesn't matter as I'm gonna put 4 GB in anyway) - Bluetooth 2.1+EDR vs. Bluetooth 2.0+EDR I'd be happy to give up those minor upgrades for $250 less. I don't think I'd notice any performance difference. That's not the issue. I'm concerned that they made some hardware changes and minor tweaks between the two versions to correct any flaws they found in the first generation of the Aluminium iMacs (Rev C as linked above). Any comments? Thanks!