I believe that most of the Kohler toilets are using "Ingenium" concept, as are the Cimmarons so fondly referred to in the earlier emails concerning clogging.
Go with Toto but nothing less than the Drake or other G-max Totos.
We have Kohlers and Totos in our large house. If for some strange reason you want do your part to keep the international trade deficit more balanced, the Kohler toilet should be a "comfort height". The Kohler toilets in Comfort Height do flush well. And, for the record, one member of my family can clog a Toto Drake once in a while.
Most Toto's are made in the USA, but after the workers, rents and taxes are paid, profits do go to back to Japan. Should you care?