Recently, I had to re-seat a leaky toilet.  When I removed the toilet, I saw that it had two extra deep wax rings as it was previously reseated after tiling the floors and the flange was very deep.  Researching online, I came upon your FTS-4 Wax Free toilet seal.  Following the instructions, I cleaned around the sealing area and attached the product.  I had my doubts.  When I was re-installing the toilet, I accidentally dropped it.  Needless to say, I am now looking for a new replacement.  However, as a test, to see how tightly the seal was attached to the toilet, I tried to pull it off.  It took some effort.  In fact, the sticky gue came off the rubber but stayed on the toilet.  I was really impressed with how well it attached it's self to the toilet.  I am looking for a new toilet, but will definitely be picking up another FTS4.  Hopefully, I will not drop this one :) 
Thanks for creating such a great and mess-free product.