MIM= metal injection molding, resulting in net shape parts.
I believe the shortcomings in MIM manufacture, especially in S&W's experience, have more to do with the durability of the powdered metallurgical material substrate than of the fit, finish, and function of the parts produced.
The aggregate pieces are produced to very exacting and very finely defined tolerances, but they sponateously fail through delamination due to galvanic effects and corrosive reactions.
Uhhh......yeah......what HE said.