The Gerber gravity toilets use generic parts as do the Mansfield.
The Niagara uses their own parts, so you would need parts from them.
What price range are you talking about?
There are plenty of "builder grade" toilets "spec"ed in.
They are my bread and butter replacing them. But I know where the builders are coming from, I did some home building myself.
A "Competitive" toilet is meant to fill the hole and get the home sold. Many of my customers have me come over on "move in" day and pull all of the competitive toilets and replace them.
If you are really looking at something better, I would suggest something in the 500 gram range, nothing below.
Spec a model that has parts that can be found at Lowe's, and a model with a good track record.
Toilets that I remove are the Mansfield Alto, and Gerber Aqua Saver.
Toilets that I refuse to sell because of repair issues are the Niagara. I got tired of having to carry two of everything in the truck to complete one install.
And you can only get parts for the breaking handles from Niagara.
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