My dad retired from a job as a material control manager in a plant that made vitreous china fixtures, and he despised Fluidmaster valves.
But I have one in my toilet. They're cheap and easy to replace.
House came with a grand old toilet that was probably 90 years old. Brass parts in the tank, nearly indestructible. But nothing modern would fit when the seals and stuff started to leak, and I finally replaced it.