Hi  

Lots of old posts about this but nothing recent so just checking that my understanding of the process is correct.

We have several products that are eligible, our speakers are play:1 and play:5. We cannot at the moment afford to buy new versions of everything and are wondering if we were to choose the upgrade process are the old devices rendered unusable by Sonos? (Software update that stops then being used for example) or can they continue to be used. 
Also does the discount have to be used on a like for like product? therefore we couldn't upgrade our existing play:1 to a 5 for example?

thanks in advance