I was looking into buying the cheaper of those two and the cheaper one is in fact better. Not all, but most people who purchased that were getting overclocks around 250mhz @ 2.5-3-3-8.
Silly me, I went ahead and got the DDR500 version (black) that has crappy timings (3-4-4-8 @ 250) and it ended up being DOA. I regret that one, wish I could exchange too.