Over the last 30 years I have sourced several new roto-molded tanks. One was a new holding tank to give us more capacity.
The only water tank I ever had to return to the retail vendor was a Krakor. They had "over cooked" it during production and the smell would
never go away.
Not much of a statistical sample I admit, but I can say that the Ronco folks seem to get the higher kudo's from other boaters and so far will remain my first choice.
FWIW, as boating expenses go, the cost of a new tank direct from Ronco was one of my less-expensive purchases!
Note B: deal direct with Ronco and be assured that your drawing of exactly where you want all of the openings will be faithfully produced.
... Just another data point....
L