Omega, have you ever played with timings?  I mean, seriously played with timings?  I have.  For hours and hours and hours.
When you are talking fractions of a millisecond, those numbers mean absolutely NOTHING.  Do you realize the difference they make in benchmarks even?  RAS to CAS doesn't do jack.  You might gain a couple of points, but when you are talking 5,000 + points, 10 points means squat.
The only timing that makes any difference at all, and even then it isn't huge, is the CAS latency.  It's so minimal it is hardly worth bothering with.
So, in benchmarks you might gain a couple of points.  But any computer tech worth his salt, that knows anything about computers WHATSOEVER, knows that benchmarks don't mean jack unless you're some little tool that hangs out at mad onion's forums.  What matters is actual performance, and you will notice little to no actual improvement, certainly not with RAS to CAS.
Besides, there are a few other factors involved here as well, ie can the CPU -> mem controller -> RAM handle it?  Not all combinations can.  I've played with those too, with much frustration.