ok, let me help you a little bit. Listen....in the Pc market there are tons and tons of great computers that can serve the purpose for what you want them, now, the difference in PC and Macs is most of all, the OS.
Of course Apple has an amazing catalog of cool stuff but regarding Computers/Hardware, Apples and PC's can pretty much do the same. Of course, Apples are the prettiest most advanced-futuristic COOLEST machines (in my opinion), but for example, Powerbooks are Pretty, slim, very weightless, but i'm just out there in PC land you can find a very pretty-futuristic, slim PC notebook too.
So my point is this......even tho Macs are awasome, and i wouldn't trade them for anything in the world, out there in the PC world you can find A LOT of cool stuff too. But when it comes down to the OS, then there's the catch 22. Windows is a very good OS, but it's kind of unstable. PC/Windows users say, that windows is a very good OS and that you just need to keep the maintness up to date, and have your firewall and your anti-virus up to date and try not to download everything you see, and not to enter this or that type of websites that may have spyware, and don't open mails that look/feel weird...blah blah.........if you do that, then you won't have a problem with windows at all................
.......BUT JESUS! they're asking you to do NOTHING with your machine!....c'mon man i mean the greatest feeling in the world about having a Mac is the freedom of surfing wherever you want, downloading anything you like, opening whatever e-mail you feel like opening....so it really comes down to the OS.
Of course i must warn you, Mac Laptops are a little bit behind - speed wise - compared to the PC notebooks. i still don't really know WHY, but apple's having a hard time addapting a G5 chip into a laptop....they'll eventually FIT IT IN there, but it's going to take a little more time. NOW, DON'T GO THINKING APPLES COMPUTER ARE S L O W, cuz they ain't. they're simple not the fastest laptops around, but after being a PC users for 13 years and a recent switcher, i must tell you that i don't know why, but in the Mac world (mac programs, mac applications, mac computers, etc. etc.) things don't feel slow, at least not in my case. i pretty much do the SAME things you do. and so far not a single problem.
so thin about it, but if you're going to be downloading stuff, working with media, and if you just plain and simple want a computer that is COOL lookin, SLIM, FUTURISTIC, JAW DROPPING, RELIABLE, WITH A TITANIUM - HARD ROCK ALIKE, STABLE OS, then the Powerbook's your machine. I tel you this as a Powerbook owner as well!
Good luck.
P.S. Sorry for the looong post but i had to really help you with a GOOD non biased opinion!