Dell XPS System

I know, it's another 'I wanna get a new computer, is this a good setup' post. It's been years since I built a computer, and i've never owned an intel system before. Some people recommended the Dell XPS systems, so I got onto the Dell website, and custimized one to see how much it would cost. Is this a good deal? Any idea how well this system would handle FSX. How much difference would an additional 2GB of ram make, and would it be worth it?
Dell XPS 710
Intel Core 2 Duo Processor E6600 (4MB L2 Cache,2.4 GHz, 1066 FSB)
2GB Dual CHannel DDR2 SDRAM at 667MHz - 2 DIMMs
768MB NVidia GeForce 8800 GTX
320GB Serial ATA 3Gb/s Hard Drive (7200 RPM) w/Databurst Cache
Dual Disk Drives: 48X CD-ROM + 16x DVD+/-RW
13 in 1 Media Card Reader
Integrated 7.1 Channel Audio
Windows Vista Home Premium
$1800
Dell XPS 710
Intel Core 2 Duo Processor E6600 (4MB L2 Cache,2.4 GHz, 1066 FSB)
2GB Dual CHannel DDR2 SDRAM at 667MHz - 2 DIMMs
768MB NVidia GeForce 8800 GTX
320GB Serial ATA 3Gb/s Hard Drive (7200 RPM) w/Databurst Cache
Dual Disk Drives: 48X CD-ROM + 16x DVD+/-RW
13 in 1 Media Card Reader
Integrated 7.1 Channel Audio
Windows Vista Home Premium
$1800