I do work for a whole bunch of credit unions in WA state. In general, they are great. But as someone said, not all are created equal.
Some of the largest can operate similar to the large nationwide banks. And some of the smallest can be so mismanaged that I wouldn't risk my money there.
I'd recommend a mid-sized local CU that has been in existence for at least 20 years (that number is based on a couple of factors that I won't bother to go into - but it's not random).
There are regular mergers and acquisitions of credit unions and you want to be in one that is the surviving entity of a merger, or one that is an acquiring credit union - which would indicate strong management and sustainable growth. The ones that get gobbled up in acquisitions are often on the ropes or poorly managed.
You can research a local credit union here:
https://mapping.ncua.gov/ResearchCreditUnion