I quite often (daily) switch between "automatic" and manual DNS settings.
On the Xbox360, it remembered what I had entered for the manual settings (primary and secondary) so that I just had to select manual to proceed.
The Xbox One forgets the previously entered DNS settings so I have to look them up and "type" them in each time.
In case anyone with sufficient power is reading, please can someone add "remember manual DNS entries" as a change request?
Thanks. Much appreciated.