Well, if you're not much of a pc freak, then Mac is indeed your best bet. And if money's the issue, you better save up or become a geek.
My roommate has a MacBook Pro (the i5 @ 2.45Ghz one) & I got a cheap ass Acer (also i5 @ 2.45) & I pretty much outrun or evenly run any of the music development software. But that took me lots of time to configur. But well worth the 600 euro I didn't have to spend. His Mac does kick my ass when it comes to battery life. This also has to do with screen size & such but that's not the point, he still pretty much doubles my battery lifespan.
Asio4All is indeed a must, and even then not perfect. I dont have a slight clue about the Mac drivers (as I dont really care either :$), but those seem to work fine out of the box. It also seems like he has a firewire port, which could be really useful.
I've no experience with live performing (YET!), so I have no clue about that. There's most likely a reason that all 'professional' artists use a Mac. But they're artists, not IT'ers, so I would have no idea on that part. I'd really love to do live performing with a PC in the future.
I'm not a Mac hater, I just prefer Windows (or even Ubuntu, but not for producing/performing/gaming).