The answer is, it is a "motley crue"... I can't name one specifically. For many it is an issue of weight. I have a demonstration cab with one Private Jack and one Red Fang in it. Even though Josh's cab is semi-open, many prefer closed backs... Those, who don't have any financial (or muscular) restraints buy a 4*12, mostly with alnico Red Fangs.
If you are happy with your cab, you will be happy with the MP hooked into it. You guys know this better than I do, but if you have, say, a M*****LL 2*12, be sure that it can take the 75W, with a 4*12, this is not a problem, but otherwise you just blow the cones away...
Eero