Well, I use it to make phone calls and not to watch TV. But I can answer yes to whether it works with Swisscom's internet infrastructure. I use it in this configuration with two handsets.

Yes, but I watch Swisscom TV via TV-Air. So I can't confirm whether it also works with the TV box (but I assume it does). It would be very strange if it didn't work in the Swisscom universe.

Another question is whether the memory locations of the phone book are sufficient for one's own needs? Everyone has to answer that for themselves. By the way, the Davos also has an Eco mode (although it does not appear in the digitec filter)!

I have been very satisfied with the HD Davos for several years! But I don't make too many demands on a DECT phone either ...