I've gone twice but haven't signed up yet. I like to lurk and read like you can on these message boards without signing up.
I used to check the threads on OTWA every few days and had been a member there since they were very small. I think their decision to limit and put a tight thumb on people like myself was to their detriment. You can't have me spouting ads but I think it's important to hear from the leaders of companies such as ours. The main reason for the decline though is that everyone just uses eBay's boards. Which isn't a good thing because you can't really talk freely there.