Is mem with low timings worth it?

[TheSpoon]

Planning to build some kind of A64 system (either 939 or 754, haven't decided yet). I don't plan to overclock (at least not until a few years down the road). Is it worth spending a few hundred (or so) more for low-latency RAM? Is the performance increase tangible? The memory I'm considering right now is (two sticks of) "Kingston 512MB DDR PC3200 KVR400X64C3" - has timings 3-3-3.

edit: I'll mention my current system, it's a 1.33 Thunderbird @ 1.46 w/ 512MB Infineon PC133 and a GF4 4200 (archaic by [H] standards, eh?).

Thanks