I opened an account as a teenager and saved up the princely sum of IR£500 towards my first car. Wanted to borrow £1,500 for the car but needed the £500 for insurance- insurance was 20% of the value of a 2 year old Ford Escort! Ended up borrowing from AIB! Over the years, it's been a convenient place to cash or lodge cheques borrow small amounts and I became a director for many years. When the banking crisis hit, credit unions were the only place lending. In good times, nobody needs the credit union but, when the financial institutions tighten up, they can help a lot of people. However, in the past 15 years or so, the Central Bank has greatly increased supervision and regulation of CUs.
I stay now mainly for the insurance, but it is a dark art and it's not obvious how payouts are calculated.