Experience with Unions/Union Jobs?

Lately I've been curious about peoples experiences with unions, both in the past and current day. What's it like to have an active union, with people interacting with its organization? Doesn't have to be a positive experience either, since my union hasn't effectively reached out to or interacted with the workers its suppose to represent. 

It would just be nice to know others experiences within unions outside of surface level union websites and such. Just to have a better general understanding of how unions can be, or cannot be, successful. 

All advice is welcome :)