MIM is okay if it's done right. I've had more than a few MIM parts not take bluing touch up at all. Weather MIM is good, it's still a money saving process on the manufactures end. I'd personally rather spend a little more and get bar stock or forged steel.
That being said, if it works then it's not too big of a deal. It's a pocket gun meant to save your life, but I know how gun OCD can be.
The thing people forget when talking about MIM in the automotive industry or something similar that makes larger parts is that there's more room for error. A small imperfection in a 3" diameter arm is different if the same sized imperfection is in a tiny hammer, trigger or internal part. I know any new gun I buy from now on will have MIM or cast parts unless it's something like my DW Valor, but that's why I've only been looking at the used cases.