BCC Hardware compares 3 Patriot Extreme Performance 2GB kits, the PC2-6400 Eased Latency and PC2-6400 Low Latency Kits and the PC2-8500 Eased Latency Kit.  You get an idea from the review that while the Eased Latency kits are much cheaper, with a little overclocking they end up a better deal than their low latency cousins.
“As you can see from the results above, memory performance on today’s Intel Core 2 Duo systems has more to do with CPU speed than actual memory speed. When three different sets of Patriot memory are compared, all three produce similar results. The kit that impressed me the most though was the “cheapy” DDR2-800 “Eased Latency” kit. This kit ran at CAS3 at an amazing DDR2-879 when it comes clocked in at stock 5-5-5-12!”

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