I'm not totally sure if it works yet, but I love hitting the button as I leave the shower, just because it makes me feel like someone's cleaning up.
My parents have this and I've never seen the shower look so good. With 6 people using that shower for 20+ years, it's a tough job. You just have to remember to step out of the shower before it turns on. Apparantly my dad hit the button then stood there staring at it waiting for it to start and had to jump out when it started. :-) He said he was squeaky clean that day.