Jim, I hope you don’t mind me adding some clarifying info for you.
Currently, Jim’s team is using a Switchvox phone system and, to my knowledge, they are happy with the platform. They are simply looking at the possibility of using softphone apps with the existing Switchvox (on-prem) system.
With that in mind, as a Switchvox reseller I can tell you that we have several clients using the official Switchvox softphone application on iOS and Android devices. Overall it’s an “OK” solution, but we have not found that softphone application to be nearly as reliable as we would like. For light phone users, it works quite nicely with some occasional weirdness (incoming calls that sometimes don’t ring through is the biggest challenge). For heavier users, it’s not a solution we currently recommend.
Now, on the macOS/Windows side of the house, things are different. Digium does not provide an official softphone application for these platforms. So you have to look at 3rd party solutions. There are several and some of them are really solid. Most of the free ones have quirks that have stymied most people we’ve worked with that tested them (in-app ads, limited features, etc.). So when you then look at the cost of a good softphone app compared to the cost of the low-end Digium phones, it’s harder to find the value in the softphone solution (cabling not withstanding).
SOME people/organizations really like the concept of just having an app on a computer and using a headset. But our experience with churches is that this normally isn’t the preferred method. Church staff (in general) really prefer the physical phone (or just continuing to use their cellphone directly).
I won’t tell you it can’t work. It definitely can. But culture and expectations play a BIG part in making something like this successful. It really is organization specific in that regard.