The Good: The Sonos One integrates both Alexa and Google Assistant voice control, with better sound quality than any smart speaker at its price. It offers smart home controls from both systems and its far-field microphone performs well. The Sonos One works seamlessly with Sonos multiroom system and can pair with a second One for stereo sound. It also supports Apple AirPlay 2 and Spotify Connect. The Bad: The One costs twice as much as an Amazon Echo. You can't switch between the Assistant and Alexa on the fly, and need to run setup again. It doesn't work well if you have an Echo within earshot. There's no Bluetooth. The Bottom Line: With excellent sound and the choice of Alexa or Google Assistant, the Sonos One reaffirms its place as the best smart speaker for the money. Since it debuted in late 2017, the Sonos One has been my favorite smart speaker overall. It costs more than the Amazon Echos and Google Homes of the world, but it's still relatively affordable and sounds much better. The first smart speaker designed with music in mind, the One still rocks the socks off any competitor in its price range.The One debuted with Amazon's Alexa voice assistant on-board, and in 2019 Sonos finally delivered on the promise of adding Google Assistant, too. The ability to choose between the two major voice systems further ups the One's appeal, especially to Google households. Despite some teething problems and a slight lag when requesting songs, voice integration on Sonos works very well. And its flexibility extends beyond voice, offering compatibility with many standards, including Apple AirPlay 2, Spotify Connect as well as the company's own superb whole-home audio system.You can find better-sounding smart speakers, including the Apple HomePod and the Google Home Max, but both cost more and lack the One's universal appeal. The One is also half the price of the Sonos Beam sound bar, which also offers dual voice assistants. So does the the Bose Home series, whose entry-level 300 model could pose a threat to the One (look for a review soon). The smart speaker competition is just getting warmed up.In the meantime the Sonos One offers the best combination of versatility, sound quality and affordability in any speaker you can buy, period.Editors' note, May 30, 2019: This review was conducted on the Gen 1 Sonos One, but a Gen 2 version is now available. According to Sonos the new version has an updated processor and more memory, but is otherwise identical. We haven't tested the new version, but we expect sound quality to be the same.Choose your partner: Alexa or Google AssistantJust like the Sonos Beam, the One doesn't let you choose between the assistants on the fly. In other words, the speaker won't respond to an "Alexa" command first and then a "Hey, Google" command immediately afterward. To change between the two you will need to run setup again.In testing both voice assistants, I found that results were almost instantaneous when asking for the time or a weather report, but requesting a song was relatively slow. Whether I was using Alexa or Google it consistently took five seconds for the speaker to acknowledge the request before playing it. By comparison the Klipsch The Three took three seconds.There were was one minor issue when initiating radio on Alexa (which defaults to Amazon Music): I couldn't transfer the music to a Sonos Google speaker since it doesn't support Amazon. Sonos may talk to both services via the app, but Amazon and Google are still on uneasy terms when it comes to their voice assistants.Four things Amazon Echo and Google Home can do that Sonos One can't (yet)The Sonos One behaves pretty much exactly like an Amazon Echo or Google Home speaker -- including features like Continued Conversation -- but it lacks a few of the capabilities of those speakers. Here's a rundown.Alexa Calling\/Google Assistant Calls: Echo speakers can call other Echos and most phones within Northern America for free. Likewise Google Assistant can also make voice assisted calls. Unfortunately, Sonos One is not able to do this.Voice match: Users can train the Google Assistant to recognize their individual voice which helps for setting alarms and organizing calendars, but Sonos can't yet.Routines: Routines are a set of tasks that Google Assistant can perform with a single voice command -- for example "Hey Google I'm Leaving" can turn off all of your lights and the TV. Other functions that Sonos can't yet perform but Google Assistant can include purchases and interpreter mode.Zigbee: The Amazon Echo Plus allows for users with Philips smart bulbs and other Zigbee-based devices to operate without the need for an external hub. Of course Sonos can control all of the smart home devices that a standard Echo or Dot speaker can. \t \t \tCompact design, expansive servicesSonos speakers have been around for 15 years and we've liked pretty much all of them. The One looks almost exactly like the Play:1, and retains the same dimensions: shorter and wider than the tall, slim original Echo. Sonos' top panel has a completely flush surface with a cluster of touch-sensitive buttons, lights and a dotted ring. Above the central light is a "mic" button that lets you mute the onboard microphone array of that dotted ring. Just like the Play:1, the Sonos One is available in white or black (pictured, though the black color scheme is different than that of the Play:1). If you're an existing Play:1 owner, it's worth noting that you cannot form a stereo pair with a One. It's either two Play:1s or two Ones.