The victron Energy one uses Peukert effect to compensate for charge and discharge at different rates. I have no idea what the others do.
They are really state of charge indicators, not energy meters, but the victron at least has readouts of charge in and out over a period.
Ultimately you need to finally determine when you are fully charged. They arrive at this point from data you give them and some assumptions they make about state of charge at a time after reaching a certain voltage and the way current is falling but you need to correct this point occasionally.
True energy meters would give you information on energy produced but would be useless as a state of charge indicator. You need charge efficiency with a basic AH meter for fairly constant loads and if the load changes much you need a reasonable correction for Peukert effect.
Flux