Let me throw in one thing that bugs me a little on my ZTE. They have disabled the factory VOIP dialer and I am struggling to find a way to integrate the dialer. I have an ATT global data sim in slot 2 and normally a ProjectFi SIM in slot one. At .20 a minute for the occasional non-VOIP call, global texting, backup data, it is a combination that I can't beat, but I find the dialer integration frustrating. When I tell the Google Assistant or Android auto to call a particular number it always goes out via ProjectFi.

I'd love to hear about the various other dialers. Also vaguelly interested in lines on the Galaxy S8 Duos which is currently only available in a few countries. I'm presuming the Swiss model will be the gray market model that hits US shores.