I think that what Mosel does is specify, pick and test memory, rather than make it. They may make/assemble the dimm modules, not sure. Probably farm that out to on of the jobbers like Jabil Circuit if they do.
I think that some Mosel memory is probably Micron, just like all of Crucials. It is possible that they have a higher cut off point for testing and qualifying memory. E.g. 150mhz cas 2. Some Crucial will make that, some won't.
For Althon buyers, only the KT133a board owners (FSB 133/266) should even begin to think about this. Really then it is only the extreme overclockers amoung them. And FSB overclockers at that.
In Intel land, the only way of overclocking the processor is by upping the fsb. Therefore, memory's top fsb speed is crucial for an intel overclocker. When you start to over clock 10% and more beyond the fsb setting, however, you are very likely to create system instability with things like disk drive controllers, raid controlers, sound cards, some lan cards, etc.
In Athlon land, the primary way of overclocking is the multipler unlock. Upping the fsb a bit is a tweak. I don't plan to run my fsb in my soon to build system beyond ~143 - 146 myself. I want my baby rock solid.
Crucial 133 cas 2 will run cas2 at that nearly always. I'll leave the 150-160 fsb bragging rights / instability to someone else.