I have used the self-wash here, and it is all about convenience! You take your dog in when you have time, they provide you with everything you need, and you only spend the time there that you need to wash your dog. I love being able to clog someone else's drain. The staff is very friendly and encourages you to spend time with your dog. They always tell me to 'make a mess!'
They recently re-modeled the self wash area so it is much nicer than before. Only down side is cost. I was charged 20 dollars a few weeks ago (I do make quite a mess.) but for 5 dollars more I can get a groupon for a full grooming session elsewhere. Less convenient yes, but better value.