zreynoldsp this used to be the case however now that centrino started kicking ass and Intel introduced it's core duo's it's pretty damn close. It's not so much the processor at all because laptop processors have been benchmarked at faster than pentium 4 3.4 ghz processors (the 2 ghz Core Duo's).

This does come into play though with bus speeds as laptops create a lot of heat so bus speeds are often limited to 533 Mhz even on the higher end laptops, whereas desktops are going at 1GHz and faster.

The difference between a mac laptop and desktop would be a lot more noticeable than the difference between a pc laptop and desktop - which are pretty similar, because the mac G5's are dual processor, dual core 64-bit and are massive and even at 2.5Ghz they run RISC.

The harddrive issue can be remedied with external firewire hard drives which are dirt cheap, basically just a normal pc harddrive in an enclosure (enclosure = 50 bux, put whatever hard drive you want in there).

The MAIN MAIN MAIN issue in the laptop vs pc debate is that laptops are going to be twice the price (as a general rule). But as Intel has been pumping more money into their portable chipsets (this is the main reason why laptop market hungry Apple signed the contract) laptops are pretty damn awesome in terms of performance.