Ragnar Skanakar used to shoot a MC55 as does Frank Dumoulin, currently. Both have won World and Olympic Golds (I think?) with these pistols, so I guess they can't be ALL bad. I'm glad no one told them they were junk. They'd probably have a different opinion anyway from the obviously knowledgeable(?) contributor, mc55.
I've used one and they are are a really beautiful pistol but with many delicate parts and a complex trigger but it shoots like a dream. But then each to his own I guess. They are getting hard to find because no one can afford to make a pistol of this complexity and quality these days.
By the way, the correct nomencalture of this pistol is the MU 55-1, except
that it isn't a "U", it's the russian letter that looks like a "U" but has a little stem at the beginning. Look it up if you really need to. Anyway, this letter is pronounced "tsay" which is near enough to our english "C", which is why you will sometimes see the nomenclature written as MC 55-1.
Today's bit of useless trivia.