IMHO..i think design also gotta do with graphics cards ( in 3D la ) since graphic card will help to boost up perfomance while rendering and also when modeling. i've experienced differenece modeling maya in geforce fx 5200 and ati radeon 9600 pro.. both of them deliver different output and the powerful card will render faster ( i mean when playblast, when u want to see the actual output when modeling it at the same time. ) it's my experience la i donno others how..

i think the screw up file maybe extension conflict when u install new software.. like when installing acdsee .. they tend to force all files can be opened through acdsee viewer.maybe lah. since till now i din hv any chance using a mac.. i cant say anything about mac.. but would love to have one :D