Elegant tub!  My one complaint is that while the drain is centered in the specifications  the 2 1/2 in. drain line should be 3-4 inches off center. Buy the tub early, unpack it, and look underneath at the strange drain line arrangement prior to your rough in and tile work!  It will save you some heartburn! I think it is a must to seal to the floor for stability and safety, but you won't find better lines  on a tube.