I checked a few countries (swap country with the link at the bottom of the page) and all I looked at seem to now be 30 days.

https://www.sonos.com/en-us/legal/terms#legal-terms-sale-returns

Yeah I checked a few and didnt see any at 100 days. I guess it’s sort of inevitable that they change this to unify return dates across their different virtual store fronts as they sell on Amazon, eBay etc.
 

I’ve never really used the 100 day return policy but there was always extra piece of mind in knowing it was there. 

Is a product in “new or as-new condition” if the software has been installed and the unit operated?

It should be but I’ve had returns to other places denied because I was missing a slip of copy-paper with a note on it.

Learned my lesson, now with anything I open I put every scrap of paper and packing, to include shrink-wrap back in the shipping box and set it aside until I’m past the return date.

What is PSA in this? I had thought in the original post it was Public Service Announcement, but in this post it sounds like a retailer. 

The post above yours is a bot. PSA is public service announcement.