Automatic Toilet Flusher
Early in the article you mention the trap not being "porcelinated" which I assume means glazed. Whetther the trap is glazed or not does not impact the performance of the toilet. If the glazing is not done correctly, snags can be created which catch toilet paper and affect the performance of the toilet.
You must also look at the size of the trap or passageway through the toilet. Most toilets in the USA are of the siphonic design in which a siphon is created to pull the waste down. In order to create the siphon, their trap must be small and they will glaze it to maximize their performance. But the small trap tends to create clogs.
Caroma uses a washdown design in which all the water comes from under the rim and washes down the bowl. Caroma also uses a 3.5 to 4" trap which will not clog, and in some cases can pass a baseball. The trap in a Caroma toilet is usually unglazed.
I would suggest you ask for the Sydney 305 from Caroma. It is their new low cost model. It will flush 700 grams of solid waste on the half flush and 1000 grams on the full flush. Note that Caroma is the only toilet manufacturer to test their toilet performance on the half flush.The two toilets that I selected were the Caroma Caravelle and the Toto Aquia
Both have a dual flush mechanism, allowing the user two options for water usage depending on what they are flushing and how much water might be required. (1.6 and .8 gallons for the caroma and 1.6 and .9 gallons for the Toto. Compare this to older models that typically use between 3 and 7 gallons per flush) Both have what I would descibe as modern lines...mainly an aesthetic based on functionality, not traditional toilet aesthetics and nostalgia. Both have sleek bases that are easy to keep clean...not a lot of nooks and crannies for dust and bathroom scum to collect.