I have only really used two Apple OS's, both with school computers...
When I started elementary school our computer lab had some kind of computers... I know they were made by Apple I can't remember what the OS was called. We had these from the time I started kindergarten in '99 (and they were not new at the time) until I was in third grade or so when the school district started to upgrade to HP machines with XP. I can't really comment on it too much because it was so long ago and I don't really have much experience with the contemporary Windows OS (which I would assume would be 95 because it certainly was not up to the same standard as 98).
In the past couple of years my school district has been renovating all of the schools, and as well we've been getting funding from Pennsylvania's Classroom of the Future program we've been getting lots of fun electronic toys. This includes computers and projectors in every classroom and (with XP of course), for the Art and English departments, Macs.
In middle school we only got to use a desktop in the Art room with OSX (as far as Macs go at least, we of course had HP's all over the place). I should say, the second year we got to use it, because the first year it sat and collected dust because it never worked. Apparently the second year it was there it was trouble free, though. It was used for Photoshop and Safari so considering they probably spent twice as much on it as on the HP's and it couldn't do anything special it was totally worth it, because you HAVE to get a Mac if you're doing anything artisitic, because Macs are better at that for some reason.
At the high school every English classroom gets 30 or so Macbooks. I have to keep in mind that this was the first year we had them but.... well...
I don't really like laptops in the first place so that wasn't exactly a great experience. Usually about 5 or so of the Macs would be missing from each classroom because they refused to work for whatever reason and they had to be sent somewhere or someone called in because no one knew how to fix them. As far as my personal experience with the interface goes, as someone who's pretty much only used Windows machines, I found it totally bass-ackwards and generally retarded. On top of that, the things performed miserably... near the end of the year I was playing a flash game on it for about a half an hour with it on the desk, and when I took it off and put it on my lap it was HOT... and then it froze as I tried to log off.The only thing I really liked was the touchpad which was better that any that I've used before. All in all it was a worse experience than using my sister's miserably bloated two year old $600-ish Acer laptop with Vista (which I put W7 on and now works pretty well, I dual boot Windows 7 on this machine now and I have to say I like it a lot).
In comparison to the miserable failures that the Macbooks were, all of our HP's are up almost all the time (I say almost because even though I've never had a 'don't use that computer, it doesn't work' personally I'm sure it's happened a few times throughout the year), and if anyone has a problem XP is so familiar to everyone it's a pretty easy to get someone to fix it (like another student/teacher, not sending the thing to admin like the Macbooks

)
Personally with my, probably biased experience with Macs I would never buy one, mainly because I play games.