Our old toilet worked fine but we needed some changes, so we got this new one.  It is a bit taller, so easier for disabled to get off from, the seat is longer, to accommodate a bigger person.  We have a holding tank for our sewer system, and the low water use option of the new toilet will cut our pumping frequency by more than half.  AND a biggy is the fact that the thing is enclosed and smooth, which will be a huge benefit in keeping it clean!  It went in perfectly, with a lot of grunting and groaning because of the weight.  We are very satisfied with it and glad we made the change.