My own take on this is that MIM was invented to make tooling tough enough to cut the newer super alloys. If done right, MIM parts should be pretty much indestructible.
On the other hand, I don't like additional firing pin blocking systems in a 1911. Why add complexity (and possible failure points) you don't really need?
If I were looking to buy a Kimber, I'd look for a pre-II gun. On the other hand, for $600 I might learn to like a II.
Randall