I used to work at a CMMI Level 5 (certified) shop. The process was inevitably tailored to the lowest common denominator. It was meh.

We used to say that the process will never turn a mediocre engineer into a good one but it will absolutely turn a good engineer into a mediocre one.

In general, I've observed that a lot of these heavyweight processes are used as a substitute for high quality engineering leadership. They are not a good substitute.