Game Performance: Quake III Arena
3D Performance: 3DMark 2001 SE
Looking at the benchmark results, you can clearly see the potential of RAM. In terms of percentage, the differences don't play a very important role, but when you consider the usual performance differences in motherboard comparisons or the small performance increases within an individual processor series, CL2 memory is a must.
Above all, fast memory is a great purchase when you consider the slight difference in price. And, if you are planning to overclock your computer in the future, your efforts are sure to be more successful with brand-name modules than with 08/15 DIMMs.
If you are gearing up for the future, look out for modules with 166 MHz memory clock (DDR333 or PC2700), which can also be run in CL2.0 mode. As of yet, these modules are still too rare and too expensive, but they should become increasingly available in the months to come.