I find that I pretty much get one thing out of design conferences: relationships. And building relationships with people that are good at what I want to be good at has truly benefited me. Having enough acquaintance to message them directly & ask a question or get their feedback on a design.
The talks are fine, sometimes good, rarely great but that's to be expected. I can never sit for a whole day and just listen to stuff, either. I have a certain capacity for information and once I reach it, my brain shuts down and says "no more!"
So, then the real question for me is - who will I see? Who will I possibly have the opportunity to meet or hang out with? There are a lot of very talented folks in the web design world.