Are there any intrinsic issues (heat, etc…) with using a higher capacity (60gb or 80gb) drive?
Storage capacity isn’t as much of an issue as is hd current draw. For instance, 7200 rpm drives draw more current and generate more heat than 5400 and 4200 rpm mechanisms. Higher speed drives will have less runtime than lower speed drives. In general, the heat generating from the drive will be no more or less regardless of the hd size and capacity. The internal box temperature sensor shows internal temperature on the front panel.