Good, but forms small tears
We are on our third snug-tub.  It is just the right size for a toddler and we are able to save a lot of water by not having to fill the entire tub.  However, they do start to wear out over the course of about a year.  Our previous ones started developing leaks that we couldn't find and patch.  I had to do a small re-inflate at every bath time.  My guess is that over time tiny rips start to form at the seams.  If it wasn't for the mystery deflates, this would be a 5-star tub.
Rating: 4 stars