Looking solely at DDR2 these days we don't see memory passing the 1200MHz barrier, this seems to be the limit of what DDR2 is capable of doing. While we won't see speed barriers broken here, companies are trying to improve the existing technologies with lower latencies at higher clock speeds; this is where the AMD platform generally performs better than the Intel platform.
OCZ Technologies have really pushed their line of overclocking memories, and without a doubt they have really impressed us here. The Reaper series with heatpipe cooling helps cool the modules a lot better than the standard heatsinks, and the XLC series works even better thanks to water cooling. While our modules we tested today don't utilize water, the heatsink design has done a fantastic job nonetheless; the modules ran rather cool at full speed overclocking.
Overall the OCZ ReaperX PC2-6400 Kit is extremely impressive, and is ideally aimed at users who want lower latencies out of their DDR2-800 kit with the ability to overclock. Also, if you're wanting to use the EPP feature in conjunction with an NVIDIA chipset, you have that option too.