I bought an alienware gaming laptop a few years ago, and had no end of trouble with it. First one they shipped was defective out of the box, so after some ahssle they sent me an exchange one. Second one worked at first, but then had new instability problems.
Had endless tech support calls about unusual crashes, complete with repetitive "fix" suggestions (Do you guys even READ the notes from the last call?), and had to reformat and reinstall multiple times per their direction.
Literally 6 weeks later, with nonstop attempts at the fix, finally got a supervisor who knew which orifice to speak from...and found out that the entire problem was a vid card fan. They replaced it, but the experience was...ugly.
On top of all that, I specifically got the upgradable vid card, but wasnt ever able to take advantage of it because they didnt make any further cards with the proprietary interface.
Even now the thing doesnt run AH nearly as fast as it should given its specs.
This time, I built my computer from the case up, with advice from the guys at our Hardware and Software forum. It was easy to do, saved a TON of money, and left me with a very, very fast computer....I'd highly recommend it.