Like I said, price is not my main concern. My main concern is to get the best machine I possibly can, where best means powerful, quiet, cool (though I'll probably be getting an iLap for it again) and with reasonably long battery life (4 hours or more at normal use). So the question is whether 5400 RPM -> 7200 RPM adds more performance than it subtracts quietness, coolness and low energy use.
