One quick caveat: If you have an Era 100 grouped with other Sonos speakers and you switch it to Bluetooth mode, it will then become ungrouped from your other Sonos speakers. You can play Bluetooth audio to the Era 100 and regroup with your other Sonos speakers — via the Sonos app — but it is an extra step.
Here’s the thing: As a longtime Sonos speaker owner, I’m not sure I’d really ever use this built-in Bluetooth connectivity. It’s not as easy, secure or high-resolution as streaming over Wi-Fi, and in all honesty, I’m not sure I’d ever have a friend come over, see the Era 100 and think “I’m going to hijack the music.” I’d probably share my Wi-Fi go-codes or just play the music they wanted from my own device. Point being, I just don’t think it’s a big reason to buy the Era 100 over the One (or One SL).
The Era 100 is more Android-friendly …
The Era 100 and the Era 300 support a type of Trueplay that Android devices can use. It’s called “Quick Tune” and it uses the Era 100’s (or Era 300’s) built-in microphones to get a sense of its surroundings; then it’s able to do some magic and adjust its sound accordingly.
As an iPhone user, I’ve never really had this issue — as iPhones (and iPads) have supported Sonos’s TruePlay for years — but it’s been a hindrance for Android users because, well, they knew that if they bought Sonos speakers, they wouldn’t sound as great as they could. But the new Era speakers are able to mend that wound.
It should be noted that Trueplay on iPhone or iPad is now called “Advanced Tuning,” and it is still able to tune Sonos speakers better than Quick Tune on Android. The reason is that Advanced Tuning uses the built-in mics of your iPhone (or iPad) and has you manually wave the device all around the room so it’s able to get an even more accurate virtual map of the room. Since Quick Tune relies on the stationary mics in the Era 100 speaker, it’s not quite able to paint the same virtual map of the room.