According to the Toto tech support guy, the only call he gets about the mechanism is right after the toilet is first installed. Sometimes it needs an adjustment to ensure a proper flush. I also asked for feedback from my 3 clients where I have recently installed this toilet and they all say the mechanism is fine and they love the water saving feature of the mini flush for "liquid waste". They all mentioned however that sometimes some of the "solid waste" is not completely cleared by the full flush because some of the waste hits the side of the bowl before it hits the water. By design the water level in the bowl of all dual flush toilets is low. So it might mean some extra cleaning. How awkward was this? : )

The new pre-misting feature on the washlets will help with that by wetting the bowl with a special water process that will make waste resist sticking to the bowl. http://www.poshhaus.com/store/c/186-Bidet-Seats.html

I have had 3 toto toilets in my house now for 4 years now, not one problem. Love the look and how they work well worth every Penney

I have had A Toto Clayton since 2009. I like the style, but it has to be cleaned after nearly every solid waste use. The water does not cover the sides at all. By the time I clean it, using bowl cleaner and a couple of extra flushes to get rid of the cleaner, there is no conservation of water. And the cleaning gets old fast. I am looking at other brands because we want to replace the toilet in the master bath. The Clayton is at a nice comfort height.

Toto offers a "SanaGloss" option which is a glaze on the interior of the bowl to make it smoother and it helps prevent waste from sticking to the bowl.