Why not wait and see? You might be able to continue using the Connect for years. I rarely group my Connect/ hifi with other speakers so if necessary will just put it in its own system. 

This is largely why I opted against the Port. I instead introduced a Node 2i and route audio back to the Connect via my receiver’s tape-out/monitor jacks for the infrequent times I’d like to group everything in the house together (or for whole-house streaming if any Sonos controller API’s become deprecated in the future with the entire system left “legacy”).

I see no need to jump to any changes, except consider what those changes might be if it came to it. There’s quite a bit of sky-is-falling going around now, not entirely unwarranted…. but all the same, a bit unwarranted. We don’t know what’ll happen in the coming year.

I am currently using the Sonos Connect connected via it’s digital coaxial output to my old Sony 5.1 Receiver which works like a charm. I was investigating on the difference with the Sonos Port my old Sonos Connect (gen1) is not compatible with Sonos S2. I have been reading  a lot of reviews this weekend. Most of them say that the Port plays slightly better than the Connect because it would cause less jitter over it’s digital coaxial output, except 1 review: https://www.techhive.com/article/3546333/sonos-port-review.html

They say that when you set the coaxial digital output of the Port to variable, the quality is not as good as on the Connect???

I bought a Sonos port last year and I’m really not happy with it at all. The lack of digital inputs makes it really inflexible and if you have an amp with RCA pre-amp output then you need a preamp for the port, most amps have a digital line out, but the port lacks the corresponding line in...the connect was fine in this regard. The line out works ok, but the sound quality isn’t the best, using fixed volume or pass through helps, but then you’ve got to use the remote on powered speakers rather than using the app. It’s just not a seamless product and Sonos have messed up in my opinion. Will likely be the last Sonos product I buy as this doesn't fit with any of my home audio setups. I’ve also just had wireless fail on a Sonos one, so that now only works if it’s using ethernet. The ecosystem used to be great, but I think quality is reducing.

I’m not sure which device you have in mind, but the Sonos Connect never had a digital input. In that respect the Port is no different.

What Port lacks is an optical digital output in addition to coaxial, but that’s easily remedied if necessary using a cheap coax/optical converter.

Thanks, that’s helpful. I’m looking at some alternative solutions and might sell the port on as I really wanted to use it to stream from my stack to the other rooms in the house. I really don’t want to add a DAC into the system just to get a line in to the port.