Gilbert Plumbing has learned from 40 years of experience installing tens of thousands of toilets that the toilet with the highest flush capacity results in the greatest customer satisfaction. The high flush capacity of the Vortens Vienna means that it can take more abuse and oversized material (items that are not to be put in a toilet in the first place) and not plug up.

All the toilets in the Flush-Off perform much better than any of the gravity Low-Flush toilets from the 1990's. After the turn of the century, the manufacturers have been leapfrogging each other as they find new advancements in toilet technology. Some people are willing to trade flushing performance for a specific type of look.

An analogy would be if you bought a laptop computer a year ago and are happy with how it looks and performs. Today a different manufacturer comes out with a laptop that is 3x faster and costs less then what you paid a year ago. Would you bring your year old laptop back to the store and demand they take it back and give you the new one?

When congress put the low-flush toilet requirement into effect on January 1, 1994, the toilet manufacturers were not ready with the technology to have the toilets perform correctly. This resulted in the problems that are detailed at the following link:
UA Study Shows Leaks In Conservation Theory Behind Low-Flow Toilets.

From the University of Arizona study:
"Several companies manufacture low-consumption toilets, and some makes and models performed better than others. Also, the survey of homeowners also revealed a range of performance and satisfaction. Henderson and Woodard's study reports that some of the problems with low-consumption toilets were traced to how manufacturers designed their products. The industry's standard was set at 1.6 gallons and companies were free to achieve it any way they chose. That standard, developed in 1990 by the American Society of Mechanical Engineers, was adopted in local, state and national construction codes.

Most manufacturers kept the 3.5 gallon tanks but adjusted the inner workings to achieve a smaller flush, either by using a proprietary early-close flush valve flapper, or a toilet dam. Intentional or inadvertent replacement of a proprietary flapper valve, or removal of the restriction dam can cause a marked increase in water use. A few manufacturers opted to use a pressurized flush technology that uses a sealed bladder and captures household water pressure. These toilets are also noisier and more expensive. Other manufacturers went with different unique designs."
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As explained in the above paragraph, pressurized flush technology is much noisier and much more expensive.