As an artist, designer, and a gamer I love my 15in macbook pro... haven't found anything that I couldn't throw at it (so long as it was compatible). AC:Brotherhood was trying to prove me wrong, but in the end it turned out to be a couple files corrupted during download and once I fixed that problem everything ran like a charm.
I commonly have Photoshop, Illustrator, Flash, Dreamweaver (all CS 5.5), Word, Chrome, and Steam up and running at the same time along with a Skype call and a screen-recording software (Livestream), and I keep my Adium (IM program) and Colloquy (IRC) open most of the time as well. If I happen to be testing a website, I've also got every browser compatible with Mac open since I hate when web designers don't test across browsers. I have yet to make my RAM or Processor crap out on me even with all of that going though my computer did get pretty hot before I bought a laptop fan.
I also have an Acer netbook and the difference is night and day. Not worth the $120 imo... all I do on it is use it to watch netflix or skype call if I don't feel like cranking out my Mac. It's my travel computer since I need my Mac in tip top condition for school and I also use it to test projects in a Windows environment when I need to. Thinking of downgrading to Windows XP and throwing another GB of RAM at it to see if I can at least do more than one thing without it locking up on me.