I had until recently a One for All 9210 indoor antenna.
The antenna has been in a recent test of a journal at # 1. But the antenna is far from being the result of what I ran with the Kathrein antenna had. The antenna is small, andiewandschraubbar and offers very good reception results. An extra power supply is not necessary because the antenna is fed by the power of the receiver. Of course, before the appropriate option in the receiver must be activated. I suspect that the negative customers review the speak of garkeinem reception simply forgotten this option have to be activated. Otherwise I can not explain why they did not receive me. For indoor antennas have a power supply you need namely not select this option. Most receivers that you can buy today have this option.
Conclusion: Very successful product, like everything made by Kathrein!