My husband was towards the back of the pack - finishing in around 32 minutes. (Of course, we'd also taken a red-eye from LV that morning so he wasn't as prepared as he could have been.) To give a measure - he normally does a half marathon in about 2 & 1/2 hours. He found the confines of the stairwell very stuffy, making it difficult to breath.

My cousin is a much more of a "real" runner than my husband. He's done the stairs 5 or 6 times I think with an average time of about 16-17 minutes.

Best of luck! Be sure to post your post-race!