Zeppelin, This is assuming you are already running the memory at 133mhz and not the default 100, but - The only way (I think) to overclock the memory past the 133 setting is to overclock the bus, which means you need to be willing to overclock your processor as well.
I think it is true of all Via KT133 based motherboards.
Anyway, this ram is great stuff if you overclock via the bus. Even for AMD systems it is good since upping the bus along with the multiplier is faster than just upping the multiplier.
I personally happen to like the Mushkin Rev 1.5 with mosel chips better. They were going for about $140 - $150 last time I checked. As always, with any ram you get there will be variation. One might hit 150 cas2 and another only 140 cas2