Recently recieved a new Alienware PC so I could run some of the better games available; got the machine on Sat 4-16. Initial reaction: Far out! However, note the following: after many, many, many, etc. hours on the phone with tech support, I have had to wait for the following to occur: had the motherboard replaced (waited 12 days); still waiting for a new video card to replace the one that didn't work (should be receiving tomorrow, total wait: 5 days)... The people at Alienware tech support are very nice, seem very knowledgable, and will actually complement you if they detect that you know your way around a PC, but they are all well coached in their customer support scripts and their first priority seems to be the company they work for.
Overall experience with Alienware: PC's are cool looking, but expect a "box of chocolates"; you don't know what you're gonna get.