When you go, you sign up, wait a really long time, get a 4 minute safety video, get geared up. Then you go in with small groups of 4-5 people. Just like everyone says, in your 1 hour session you get maybe 3-4 minutes of actual air time. Its pretty fun but...not much time. Most (98%) of that time the instructor is holding on to you.
Wife listed this as one of her top 3 events while in Vegas (and we did a lot). As for me...I had fun but thought it was way not worth it for the little air time you get.
A suggestion for the shop: get a reservation system so we don't waste all our time waiting around.
Hint, don't go here unless you get a $10 off coupon in just about any vegas booklet.