It's very fun. I see it as Shala's total fun sport - no real rules, other than holding the sit at the foot of the dock until I release her. And it's a chance to do big entries into water (which she loves to do) and swim all day. What more can a dog ask for?
It's funny because the first dog refused to jump, and then a Golden came out flying. We watched for a while and when we left my husband and I both thought that our dogs would love it. There didn't seem to be anything involved that they don't both already do.
Later that night my son came over and he had been at the same outdoor expo, but at a different time. He said "we should load our dogs up one weekend and try it". He has a lab that jumps from one end of my pool to the other from a sit. My pool is 30' long. We actually were afraid last year he was going to hit the end.
It just seemed relaxed and fun. To be clear I'm sure we weren't watching the very best dogs, but they were having a great time.