Mushkin doesn't make memory at all, they just "hand-pick" memory of other manufacturers, and put it through some tests in case they need to overclock it.
Crucial DDR PC2100 overclocks well for me and many others here (CL2 to 145 MHz, instead of the specified CL2.5 133 MHz).
Corsair's "2400" of course is supposed to overclock even better.
I would look online for memory reviews, just search for "crucial pc2100 review", etc.