Since the '60s I've owned my share of N-Frames. I don't have a recent production example, but handled an N-Frame owned by an acquaintance a couple years ago. Yes, it had the lock and MIM internals. But nicely finished, no obvious flaws, and a very smooth action.
FWIW, I've now owned a S&W or two with the much maligned MIM internals. As received, these revolvers have had a smoother double action than many of my '60s - '80s examples. I don't like the "idea" of MIM, but have never had a MIM part cause an issue in any of the S&Ws or other manufacturer's guns I've had....