From these benchmarks the Charybdis might look the better machine, but it's not £250 better. The performance figures you're getting from the 3XS Vengeance are so close, and on the DiRT 2 gaming benchmark slightly ahead, that you'd happily go for this more fully featured setup.

These benchmarks don't take into account the superior OCZ SandForce SSD and dedicated soundcard of the Scan machine either, both of which help make it such a quality machine.

CPU performance

Cinebench R11 – Index: higher is better

Scan 3XS Vengeance: 8.73
CyberPower Charybdis: 10.32

DirectX 11 tessellation performance

Heaven – FPS: higher is better

Scan 3XS Vengeance: 25.9
CyberPower Charybdis: 28.2

DirectX 11 gaming performance

DiRT 2 – FPS: higher is better

3XS Vengeance: 90
CyberPower Charybdis: 88