I am in the same boat. I run games till something breaks irrecoverably, or a new version shows up that has features that I really really want.
My current game has been running 5.20 for 25 years in game, and aside from the very beginning of the game (hostile race next door to Sol) its been pretty quiet. I didnt put a certain wormhole event into the game, because my last game had someone running around massacring NPRs before I ever got the chance to meet them.
The AI can be really dumb at times (feeding ships into a jump point they don't every return from) but at the same time, I have seen the AI do some pretty nasty stuff as well, like jumping a huge fleet in unexpectedly.
I am waiting for the day when Steve figures out how to code fighters in for NPR's, then things will get REALLY interesting...