Haven't been there in about 5 years, but I had some very good experiences there as well as a few lame ones. A lot of smart people there, and a lot of people who just love to bicker over minutiae.
A lot of magicians hang out there, which makes for interesting conversation. Magicians often have an insightful take on all kinds of skeptical issues.
The best times I ever had on the JREF involved situations where some true blue woo believer would show up declaring themselves to be a "skeptic," then proceed to spout all sorts of wackadoodle balderdash. So many bros with so many cool stories! So many skeptics grilling them on the details, using their critical thinking and research skills to ferret out the inconsistencies... so much deliciously creative and lighthearted ridicule!
How often do you get to pal around with fellow skeptics and actually engage with genuine, honest to god, self-professed psychics, New Age healers, ghost hunters, UFO investigators, bigfooters, conspiracists, "Freemen" libertarians, cult members, MLM scammers... the JREF attracted those people like moths to the bug-zapper.
But when the JREF forums were bad, they were really awful. A lot of the regulars in the political subforums were super-annoying.
Even worse was when the JREF became the platform for the petty infighting within the skeptic and atheist movements. I eventually quit those forums because of the incessant bickering over "Elevatorgate" and "Atheism+." That's when things really went downhill, because trolls from both ends of the political dumbbell descended on the forums to make it their battleground.