We replaced all of our Standard toilets.  The elongated bowls and chair hieght provide a more comfort level; also if you need to flush while you are in the sitting position - their is no back splash from the flush touching your bottom area, after installing our first Kohler, two years ago and placed it in the first floor half-bath, everyone provided complements after using it, therefore our other two full baths on our second floor have the same new Kohler model also.