Couldn't agree more. I've attended the one in NYC last time. While I enjoyed some of the talks (I had seen the others before), it wasn't much different than watching the videos.
The hallway conversations and the networking was indeed vibrant and full of energy, but no different than any other startup event, or sxsw, or meetups, or...
I'd say that there are smaller and more focused events (Eyeo comes to mind, even though not free and much longer), that are more rewarding. Anyway, I'd probably go again if invited, mostly for FOMO (fear of missing out).