All I can say about them is this. They have always paid me what they owed me and paid a fair market price. As for is it worth joining. Heck no! You would be better off joining the Mugwumps. I defy anyone to explain to me just what it is you are joining. Can you vote for editorial changes? Can you get stock options? Do you get access to private club land?
What you get are more than regular bills and offers to spend more money. Just buy the magaine and save the dues.