I agree, I did like my MT100, but it kept crapping out on me. Usually, as you say, one channel.
I hooked up the MicroFet already, it was super easy. It will not work in bridged mono or chB, only chA. I just discovered that my MT200 will also not work in bridged mono. :/
At any rate, the MicroFet seems wimpy at first, but watch out, it gets loud. 12:00 on the MicroFet is is like 10:00 on the MT200, but it ramps up quickly after that. It's thinner sounding, almost transparent like a Fender amp, without the bottom warmth but very much putting out what is put into it. To my ears, the MT200 seems to color the tone a bit - warmer. fatter. better. spongy tube compression.
It's very similar to my new SS combo amp, thin. I think (like my combo amp) it would pair fine with an MP-2, because the MP-2 is so forgiving. It can compensate for a bad power amp (IMHO) and still sound good - good enough for who it's for. Not that the lil' Marsha is a bad power amp, it's just not as warm sounding as my Boogie toob amp was....but it cuts through the mix