Well I hate macintosh so I really couldnt' give you a good unbiased answer.
All I know is what you know in that like OS X is supposed to be insanely user friendly and stable and people will brag 'Oh it doesnt get virus's" but...yeah that's because why would anyone bother writing a virus for a computer in which like 5% of people use?
It used to be macs were 'better for graphical purposes' but I find that to be complete BS, as you go to Pixar studios or the people who made Final Fantasy and they are using Maya 3D, and Soft image, things on a PC based machine so I don't know where this rumor came from.
Also I don't know what macs speeds are up to these days so I couldn't tell ya the equivelant of a 3GHz Intel....
I believe someone said at one point that macs are already using 64bit processors, not sure if that's true or not though.
Plus the fact of course you will have a really small selection of programs that will work on the Mac unless you have a lot of Mac friends.
I don't know, just my thoughts, as I said I'm biased towards hating em lol as I had a mac WAY back in '95 that was a whole 65MHz and 16mb of RAM lol