Karl Belkner tested the Vortex HiFi Nano Shield Power Plugs in audiophil - online and awarded the plugs the coveted audiophil - online TIPP.

His conclusion:

The VORTEX-HIFI Power Nano Shield Plugs are very suitable for optimizing the acoustic room situation. All unused sockets should ideally be terminated with the power plug. Compared to competing products with a similar mode of action, the VORTEX HIFI plugs have a very good price / performance ratio. This even makes it possible to equip several rooms at a manageable cost. In addition to the audiophile improvements, the general intelligibility of speech and the subjectively perceived room acoustics in the plug-equipped rooms will also be improved, so to speak as a free supplement.

you can find the whole test here