Yeah, that member owned part is a serious 'Pro' for me. But I don't know much else about them.
The key one is being able to open and close accounts far easier.
With my current one you have to call them, and they're only available to call on the third moon phase, while Saturn's rings are aligned with Pluto. It's ridiculously unavailable.
Edit: oh wait, I didn't read you're comment correctly. Bank Australia and Beyond Bank are both member owned and formed from credit unions? Interesting!