I've never been and I don't think I ever will. I just don't see the point. If you're a casual fan the TV coverage is better because it focuses in on the exciting stuff, and if you're serious about knowing what's going on you need to watch the All-22 tape more than once anyway because you won't take in the coverage, pressure, protection, route concepts and techniques in 3 seconds no matter who you are. Games are only fun to watch when they're close, so I just get a streaming site, watch the Jets for entertainment, then in the second half go on NFL.com to check which game is closest and watch that one.
Also if you never watch more than half a game at once you never get tempted to have stupid opinions about stuff you need All-22 tape to understand anyway.