Unions Opinion
Good Unions: Unions that fight for their workers to give them better pay and benefits. Also unions that place all their members first (no chain of command/seniority).
Bad Unions: Ones where the Union leaders are best friends with the company leaders. Also unions with capitalism goals (making tons of money).
Unions Opinion
I worked for a bad union (a local part of the UFCW). Union representative was best friends with the store manager (who was a major asshole), drove around in a very nice car, etc. I remember when the Union representative came in we all had to be in our best behavior because otherwise it would "have" to be reported to the Union. There were many cases of the Union just saying "Sucks to be you" and then just do nothing.
Corrupt unions
Ironically in non-union hardware stores (where they teach you how to say no to a Union and how Unionizing would cause the business to collapse) you get better pay and benefits. It basically is a worker trap since a few dollars above minimum is just marginally better and the benefits are always minimal coverage plans. It incentivizes workers to not even try to Unionize. All unions have to be good because it just makes thing worse.