The system BIOS has been pre-set to overclocked settings, increasing the stock 2.67GHz quad core to a mammoth 3.42GHz with a 12x multiplier and 284MHz Front Side Bus. Whilst this isn’t the massive “400+MHz” bus speeds we’re seeing on our own forums, we have to remember this is a Core 2 Quad in a system that is 24/7 stable after Vadim's in-house torture testing.
The quad-core is certainly worth it considering the potential future-proofing versus the cost of the system, and the ability to upgrade the CPU yourself is virtually nominal since the cabling is so tightly secured and routed - Vadim will do that for you if you want to, though. Considering the cost of the system, the upgrade cycle will be elongated so it makes sense if you're already investing in a hardcore system to go all the way. Here's a few shots of the BIOS configuration: