You obviously didn't try the Caroma to include it in your review with a rave. Worst toilet ever. One inch of water in the bottom and the smell that goes with it.
The poop lands on the ceramic area above the water toward the front and stays there since the front flush goes high and over the solid waste. One must clean the poop with a brush after every use and if you wait an hour or so, it dries and the typical toilet brush is not strong enough. Then you have to scrape it off.
Also, even with the double flush, while the poop that hits the water will flush, it leaves the water a soiled brown color and that stains the ceramic bowl in the one inch of water. My ceramic toilet bowl may be stained forever. I have only had the toilet for a month with one user. I am returning it to Costco after paying a plumber to install and now another to uninstall.
With the single flush, half the time, toilet paper is left in the bottom, requiring two or more flushes.
Please try products before you write reviews. Or just read some of the reviews online.=
Kelly