InsideHW.com has posted review of the Kingston HyperX DDR2-1200 dual channel kit memory

Kingston HyperX modules are made with selected series of memory chips which are usually soldered to quality 6-layer or 8-layer PCB circuit board. Multilayer PCB reduces noise in communication with memory controller, which is very important during overclocking. In this situation, things are very simple - if signals are pure and clear in communication between memory module and chipset, than it's possible to attain higher working speeds.

Kingston HyperX DDR2-1200 Dual Channel Kit Review