I installed a 1.6 gal/flush Kohler in my own house and I was amazed how well it really does perform. I don't remember the model - Wellmont, Wellspring, Wellington... something like that. I saw part of a home improvement show on TV thia past weekend where the Kohler rep tested the same model I have by flushing 30 golf-ball sized balls of toilet paper down all at once. Impressive. However, having said that, whenever I have a really big job to get done, I still retire to the good 'ol 5 gal per flush in the other bath!