I purchased a Crown XL in 2004. My wife used it for therapy for her broken back. The tub was deep enough for her to do a series of exercises she developed and even with a leg that is numb and saddle anestesia, thanks to the tub, she is able to walk.
It developed a crack in 2011. I contacted Nordic and Shawn told me to send in pictures and proof of purchase. Almost immediately I received confirmation that the shell carried a lifetime warranty. I needed to get it to a dealer, I live 165 miles from where I bought it, but Wolfgang's Spa Works in Taos, NM agreeded to be the drop off point. Wolfgang's told me that they has sold 600 tubs and had only two develop problems. I am currently awaiting delivery of my new tub and would recommend Nordic tubs to anyone considering purchasing one.