Timing Question, help me understand...

I'm not building a new system, not buying memory, just looking around and trying to learn a little more about the nuances of homebuilt PC's. Today's lesson is RAM timing.

I get the basics, Lower CAS latency is better and so on. But how much do the other numbers mean? Assuming this link works, take a look at this NewEgg comparison of two dual 512 DDR400 modules. For those too lazy to click, one is 2-3-3-6 and the other is 2-3-2-5. The price difference is a whopping $8.

Would there be any noticeable advantage in the "faster" RAM? How about in a stock configuration as opposed to CPU overclocking? If you were building a system and wanted 1GB of DDR400 RAM, would you find a better place to spend that $8?

Thanks in advance for any help, just trying to learn a little here.