Dell XPS 700

Early next year, after Vista and FSX are out, I plan to upgrade my computer (presently a Dell XPS Dimension) to a more powerful system.1. I have looked the Dell XPS 700, but recently read some nasty comments in the newspapers about this machine. Is anyone familiar with this computer?2. I have also looked at the Falcon Mach V with Core 2 extreme, and the Alienware. Is anyone familiar with either of these two products?3. I would prefer to stick with Dell because I assume I can get better tech support because it is a larger company. Does anyone have experience with the tech support at Falcon or Alienware?4. Lastly, my local computer store guru told me that if I wanted a high end powerful gaming system, he could build it at a competitive price versus Dell etc. Does this sound correct? Thanks for your help.Stanner