Yes. I tried heal spec along with cybertech and even with being able to make armor for M1 he usually had less armor than me. He has absolutely no advantage over a DPS or healer companion at all.
I'll repeat, even equipping him completely with crafted blues the best you can hope for is for him to have about the same armor as a commando healer. The only difference between doing your own tanking and letting M14X do it is that with M1 you kill slower. There's never any circumstance where he is worth using, period. Back when they nerfed tank companions they drastically overdid it, to the point where they're the same as any other class that can wear heavy armor. As a trooper, you have a healer and a DPS that wear heavy armor. Either one is an equal tank and superior in other ways.