My membership expired last month. I own a a fair amount of cameras and gear so I use their insurance. I got a monthly magazine which I always put on my desk, but never read. Members offer training sessions in things like portrait photography, which is real valuable if you need a mentor and hands on experience. The locations are fairly random, but there are enough so that there should be one for those that live near a city. I am just too busy to take a day off for that.
Perhaps the biggest benefit for those that deal with the public is getting certified as a professional photographer. You would have to complete assignments. For those that need the training or want feel being certified will get them work, this is a big benefit. For an art photographer this is practically meaningless. There is no true certification for photographers. It's not like being a CPA or certified teacher, although the public might not know that. If you want to work in advertising they want a degree and a great portfolio and likely could care less about being certified.
I do a lot of commercial work, events and family shoots but almost always is as a subcontractor or a similar arrangement where I don't the booking directly. I am on the fence about renewing, because I have lost my equipment insurance. I have not taken advantage of anything else.