the ps/2 wa a major flop. but not in that it didn't sell units. i saw a few of them in ireland in the 1980s. but owners quickly learned that expanding the computers in any way was very expensive. the micro channel bus was better and more efficent than isa that it replaced but mca cards were around 4+ times the price of their isa counterparts.
it made quite a few ibm pc buyers choose non ibm pc computers after the ps/2
My hatred of MCA was born out of keeping the magic disk. You couldn't get the bios to recognize the card until you applied the magic disk to the system.