Have an American Standard Champion 4. No problems. Went from clogging every time to no clogs.

Here's what to look for in any brand: fully glazed trapway, largest diameter trapway, largest flush valve size though this is less important.

Then teach everyone in the house how to correctly use a modern toilet--IT MUST BE FLUSHED. USE MORE WATER!!! FLUSH IT AGAIN to put enough water down the drain to keep your sewers moving. Especially if you use "flushable" wipes, which are known sewer cloggers.

Low-flow toilets are responsible for more toxic chemicals being added to the sewage systems than any thing else done in America.