I agree, the Era 300's IMHO are a better quality sounding purchase than their sister 100. Sonos has not Holiday discount the 300's as of yet!
I have one which I purchased with a trade in discount, and can wait to get the next one so I can make a stereo pair. I wish Sonos would allow stereo pairing with mixed units!
For those wanting a more robust HE integration of Sonos devices that what HE provides as a built-in app, check out Sonos Cloud Control App that @daniel.winks is developing.