I had this on a tub for a long while, but noticed the overflow was leaking.  The gasket is pressed in by the body of the tub so that the near side does not seal against the underside of the tub.  It is quite annoying.  The idea is nice.  Given that other reviews do not address this I have to imagine that perhaps it is a flaw with the bathtub (of the same brand obviously) instead of the drain, but it is impossible to tell.  I wish the gasket had a shoulder all the way around to hold it steady on the pipe, but I am not even sure that would work as holding it with my finger while tightening was still unsuccessful.