I would tend to always opt for the Sonos One, as it has twice the storage and ram compared to the SL (I believe). It also has the mics and built in voice assistant for a few dollars/pounds more. They sound the same, but I think the added features mentioned, will be more worthwhile in the long-term.

thank you. 

Neven

I don’t do voice stuff so the SL is my choice but I don’t recommend that to others unless they are planning on using it in a surround setup (EDIT: with a Beam) that would disable the voice functions anyway.

I have two Play 3s as surround. I play to put a single Play One to invite Alexa and Google to my home. 

Neven

Surround setups do not disable voice functions, they disable Airplay. (When used with a Beam the surrounds don't work for voice,  but that is because the Beam is itself voice enabled anyway.)

If the aim is primarily to introduce voice control to a room that already has Sonos speakers then there would be advantages in buying an Echo Dot or Google Mini rather than a Sonos speaker. That would require making a choice between Alexa and GA.

To be honest, I don't know. Maybe I will not be using voice service after all. Bit I would sure love to own another Sonos speaker :-)

Thank you

Neven

A very understandable feeling. And from my experience one that persists no matter how many you own. 

So true! 

Thanks, I edited my post to add that I was thinking of a Beam setup.