Fyi for the fill valve experts/enthusiasts out there. I just replaced a toto power gravity fill valve (korky quietfill) with a korky quietfill maxperformance and noticed the water level marks on the two similar valves are quite different. The maxperformance level is an inch or so higher than the regular korky. This means that the maxperformance needs to near the bottom of its height adjustment to set the level correctly. Maybe korky did this so that the maxperformance would fit inside more tanks (shorter valve)? The critical level seems to be at the same point on both of them so I am not sure that works out.