Personally I don't like Apple, they are way too expensive, the value for money is rubbish compared to PCs and i have had a Mac before and it caused me nothing but trouble, particulary with application running, I would never use one again if i could get away with it, their Ipods are alright though.
Perhaps, but the security model is totally different. The unix security model used by OSX (and by Linux, Solaris, HP-UX, AIX, etc) is very different to the Windows model (the turn everything on by default approach). Don't get me wrong, 7 is a lot better (I'm using it right now), but the number of patches released by MS every month is astounding and not all down to the number of users.
What is Windows 7 like? I still use Vista (one gripe i have, is Microsoft releasing a new versions almost every other year, can't afford it, and with Windows 8 out in the not too distant future as well, probably won't have the money for it when i go to uni, (hopefully) )