I have a question.

We've had a significant discussion about what's wrong with 50+. As I understand it the complaints are 1. Too many threads with no cycling content. and 2. Too much cliquishness. What do people think are the strengths of 50+?

I would ask the complainers what attracted THEM to 50+. There are other forums to discuss almost any cycling related topic, what made them select 50+?