my uncle has a macbook pro and its a really nice machine. Apple does make quality hardware and when you get one you prolly wont use a pc unless you have to. Does valve release steam games for the mac? Last time i checked the source engine was DX powered, not opengl but i could be wrong.
The main reason that i dont use macs is the cost. Im a student with very little extra money, you get what you can, and im happy with my little compaq. no macbook but i've got a slimmed down version of xp pro on it.
I say go ahead and get one. You wont be sorry. There is a learning curve if you are coming from windows and the bigger the windows pro you are the harder it will be. The first time i used a mac i freaked out because all of the shortcut key combos didnt work and i was trying to right click all the time. Took me forever to find out the the menus were on the bar and not in the window itself. WTF is up with that?