After unpacking the unit, my focus now was on the power consumption.
At idle, without a single cable connected to the switch consumes 8 watts.
At 16 joined cables (length each 1-5 meters) then it consumes 12.5 watts in the scenario approx.
Due to the high idle power I have returned the device back and replaced by two TP-Link TL-SG1008D 8-port switches. Thus, although I have only 14 ports (1 each port is required for the uplink to another switch) but give me this moment from.
Needed at idle without a cable switch ca 0.9 to 1 Watt, 8 occupied ports then about 4.5 watts.
Thus, both will need along with a whopping 16 cables then about 9 watts.
As for me, rarely all devices are online at the same time (ie ca 4-5) Personally I drive better with the two 8-port switches.
Who does not want to look at the last KW / h, obtained with the TL-SG1016D a good and especially robust device that has a purpose.
Who wants to have a very low power consumption, is certainly not happy with the high idle consumption. Therefore, "only" 4 stars.
Maybe they do it so to reduce the idle consumption of a successor.