If EVERY contractor you know is that (I have tried several words and cannot find one that encapsulates both my horror and disgust at the ignorance expressed by that statement) I really have no response.
I live in a house built in the ‘60s. I have replaced 2 of 3 toilets with low-flow units. The one in the basement hasn’t been used other than to keep water in the trap since I bought the house.
The ONLY problem I have had is with-—how can I put this politely?-—surprise emissions that would have challenged even an old-school 5.5 gallon Ferguson flush (ref:Married With Children).
Yes, the first low flow toilets were complete and utter garbage. The water flow engineers were finally brought in, and most of them work just fine now. If you are buying cheap Chinese crap, you DESERVE to have your bowl flow back into your ensuite.
I was leery of the new one I put in about 2 years ago. Never had a problem with it. It has two modes. (Hmm - com-mode?). Press the handle and it does a low flow - never had a problem. If you press the handle farther (done by accident a few times) it does a more impressive job.
While I guess it is supposed to use less water, the force of the water seems much more than my two older toilets.
Cheap Chinese crap is all some people can afford I’m sure.