i don't know about the m1 and m2 but the wcs-1 seems to be a hybrid of digital (oscillator) and analog (circuits).
here's the m1 solo:
hmmh, has the m1 one osc and m2 two osc? is that the difference? i couldn't find a demo of m2 and no info on either of the modules on their official web site. i guess we have to wait until the 10th of jan to get full specs. very tempting price but i wonder what the quality of the parts is...
"no one ever sweats on a plug-in" -moby