I chose the Entity because it wasn't too tall. I was remodeling my only full bath and just couldn't replace the tub with a shower. I expect to age in place in this home and I was worried that higher sides would make it harder to enter. 
I was worried it would be too slippery, but the slight texture on the bottom is enough to make me very comfortable. Plus it looks great.
The only problem was that the feet were not all level. I kept trying to figure out what was wrong with my floor to finally realize that one of the feet was shorter than the other (the front one on the drain side). 
I set the tub in a mortar bed because I really wanted it to feel solid, but it was very sturdy without it. I also stuffed a lot of rockwool insulation around the tub for sound insulation which really makes it quieter than my old tub.