Orpington Folk Club is the only one I can comment on, having been coerced into visiting it by a well meaning folkie.
It was housed in a cold upstairs room, in a not very thriving pub, or rather it was sort of thriving in a "we don't like strangers here" sort of way.
The five or six acts that performed were excruciatingly poor, and definitely fall into the celebrating their own egos category. I visited it a second time, because I could not believe it was so bad, and hoped my first visit was on an unusually weak night. It was equally poor then too.The average age was 50 plus, nothing wrong with that, but where do the future of folk clubs lie?
Sorry to not be more positive, I am sure there are well run clubs out there.