in our school here in the UK, unlike all the other high schools in the area, we are fully mac equipped (Imacs, old Macintosh's, G4 servers, the whole malarky) whereas the other schools have PC's why? after hours of arguing with the "network administrator" - my annoyingly drone voiced computing teacher, Imacs are cheaper (kinda true), more reliable (not sure about that, the stupid server always crashes), faster (bahahaha, ok well they can be quite nippy), take up less desk space and also there is also the performance indifference;e.g one mac isnt faster than the other sitting beside it.
anyway Macs are good, although PC's in our school would be better education wise as hardly any businesses use Macs do they?? but the major downfall of the macs is that as they get old, there is absolutely noway to upgrade ram, video card, processor etc so in end, they just get chucked out dont they? a bit like those real old computers that had their procs glued on..