The simple answer is 'yes', even though that's not technically correct.
If you have two RAM modules, in identical systems, and both modules set to operate at a clockspeed of, for example, 400MHz, then the system with its RAM timing set to cas latency 2 will outperform the system with its cas latency set to 3. The difference between the two RAM modules is quality, rather than speed. Both operate at the same clockspeed, remember.
But the but the higher quality module, which is capable of operating at the improved RAM timings, will work with stability in a system capable of using the faster timings. The RAM is still operating at the same speed, but the system is taking less time to communicate with it.
It's sorta like how some people are better than others at picking up everything a Rap singer is saying!