The larger and faster a RAM module becomes, the higher the latencies tend to be to compensate to ensure proper operation. While increasing clock speed generally nets better performance over tightening the timings, at a chipset size or speed cap your only room for improvement is to reduce latency. The sweet spot of 1GB modules has been OCZ's latest target in extreme performance, with their PC-4000 EL DDR Platinum
XTC 1GB Modules (available in 2GB kits). The modules are DDR500, leaving plenty of room for overclocking on newer A64 type boards, and are rated at very low latencies of 3-3-3-8 for 250MHz operation. Even more attractive, the kits are going to be offered at a lower price than than the EB series, to target more enthusiasts. Like usual, the parts will come with a lifetime warranty and OCZ's honeycomb heatsinks for XTC modules. Specific pricing has not been released yet, but I'm looking forward for when it hits the stores.