Such a disappointment. When we purchased our $22 tickets, we were told it would be a 30 minute wait... that was a lie. It was something like an hour & a half wait to get up to the top. & once up top, I wasn't too impressed. I had wanted to get up there to get some great photos & when we were finally up there, the sun was setting. Also, in the observation room it seemed that the glass was just insanely filthy... nose prints 'n slimy little kid fingerprints all over -- so much for photos.
I went to the glass floor part, which was alright, though not as impressive as I had thought it was going to be (I somehow envisioned that the entire observatory would be like this). My favorite part was the outside area -- less children screaming & less smelly overall...
Definitely something I guess you should do once, but go during the middle of the day when it's sunny if you want good photographs.