After searching this forum for Champion 4 and reading so many complaints I felt I should throw in my two cents. Have there been problems reported? Yes... but like a visit to an expensive restaurant... if you get a bad meal or experience lousy service you tell everyone but very few people go out of their way to report the good food or service.
I purchased my first Champion 4 in 2009 after seeing the golf ball flushing commercial and to hopefully combat a toilet in our half bath that needed plunging several times a month after flushing solid waste. FACT: Fourteen years on and we have not needed but plunge it once. Awesome flushing! No complaints!
So pleased with its performance in 2018 during a remodel we purchased two more Champion 4 toilets, one for our master bath and one for our upstairs bath. I can report we have not had a single ghost flush, failed valve or needed to replace the flapper seals.
NOTE: I personally installed all three toilets. During each installation I seriously cranked down on the tank to bowl bolts and have never had the dreaded tank wobble so many complain about (which occurs when not adequately tightened).
Fast forward to Dec 4th 2023... First Problem
While we found no water on the floor my wife discovered a hairline crack in the upstairs toilet bowl purchased. I completed a online customer service form explaining the issue and included a photo of the crack.
The same day, only four hours later. I received a reply email from American Standard apologizing for the problem and informing me a new bowl was being shipped out via FedEx along with a tank to toilet installation kit with gaskets bolts, seals and a new wax ring!
Awesome response with No hassles. Very impressed. Other than mentioning the model number and installation date I provided on line I did not have to provide proof of purchase.
NET: Granted I'm now faced with the hassle of having to pull and replace the bowl (basically an entire new installation process) I can't complain about the quick response and resolution by American Standard. Would I buy them again? Absolutely!
FYI ( NOT RELEVENT) : As to the ghost flushing problem and subsequent class action lawsuits... I'm not sure American Standard ever identified a net cause but I have my own suspicion. HISTORY: I live on a well which means no chlorine in the water. The reason I bring this up is I was part of R&D group testing a planned, new to market (i.e. expensive) $3K espresso machine. Within two years 8 of the 10 machines experienced main seal failures (leaks and flooding) of the boiler groups. As it turned out my machine and the other unit that didn't failure was both were on private wells. It was ultimately determined the chlorine was causing the seals to deteriorate. An new seal material was selected and the problem was resolved.