@sweller 

If I was looking at the two the first option would be the greater input since you are making the connection between the extender and router the fastest similar to using an Ethernet cable for our Deco units.

The second option I would use if my issue is distance and where I want the extender to does not see the 5G or if my client devices do not support 5G.

The High-Speed feature switches off one of the wireless bands to leave one high-performance, super-fast network, ideal for HD streaming and gaming applications. If most of your devices are connected to one wireless band, this feature can increase the overall performance of your wireless network get someone to call you spell