Editor's note (9/20/2018): Amazon announced a new, redesigned Echo Plus with a temperature sensor and other features. It ships to consumers on October 11th, 2018.

If Alexa taught us anything, it's the importance of good software. In Alexa's case, it's what made the original Amazon Echo ( ) smart speaker so compelling. On its own, the Echo itself was just your average Bluetooth speaker -- it was Alexa, Amazon's cloud-connected, voice-activated AI assistant, that made the Echo a game-changer.

The Echo Plus is frequently discounted from its standard $150 price. Check our list of Amazon device deals to see if it's on sale now.

That brings us to the new Echo Plus. At $150 or £140, it looks just like the original Echo, but the "plus" part is that it adds in a radio for Zigbee, a wireless standard used by certain smart home gadgets, including Philips Hue smart bulbs, SmartThings plugs, and connected locks from Kwikset and Yale. Thanks to that Zigbee radio, the Echo Plus can talk directly to those gadgets and tell them what to do. You don't need to plug an extra bridge or hub into your router to translate the Zigbee signals, because the Echo Plus is already fluent. It is the hub.

That, coupled with an incremental uptick in sound quality, makes the Echo Plus a good piece of hardware. The software, however, leaves a lot to be desired with clunky, underdeveloped smart home controls in the Alexa app that don't do as much as they really should. The Echo Plus has other strengths, like an aux-out jack and a new ability to launch multifaceted "routines" with a single voice command -- but they're the same strengths that you'll get with the new, second-gen Echo, which costs $50 or £50 less.

With the right app updates the Echo Plus could improve over time, and that's probably what will happen. Until it does, though, I wouldn't build a smart home around it.

Enlarge Image Chris Monroe/CNET

Looks the same, sounds the same

Enlarge Image Chris Monroe/CNET

The Echo Plus comes in your choice of three colors: black, white or a new silver option. Get it in black or white, and you'll have a very hard time distinguishing it from the original.

The way to tell is in the back -- the Echo Plus added in an aux-out jack, just like the second-gen Echo did. That'll let you connect to external speakers using a 3.5mm cable (you can also connect wirelessly via Bluetooth). That's a nice touch, but if you're just looking for an Alexa device to connect with your high-end speaker setup, you're better off just getting an Echo Dot and saving $100 or £90.

One other note: With the old design making an encore, the Echo Plus is now the only Alexa device currently on sale that offers a volume ring up top. The second-gen Echo ditched that volume ring in favor of the Echo Dot's volume buttons to help get the cost down. I prefer the ring -- it feels classier, and it's easier to use in a dark room.

Speaking of sound quality, the Echo Plus does indeed sound a little bit better than the original Echo, at least to my ear. Both are almost equally as powerful, but I noticed better balance between highs and lows and slightly less distortion at high volumes with the Echo Plus. It's a very subtle difference, and not one that you're likely to notice unless, like me, you spend a good chunk of your day listening for it.

Can’t hear much difference between the old Echo and the Echo Plus in this sound test. Both playing “Halo” by @ThePassTheBand at 50% volume. pic.twitter.com/c4JK3jno9z — Ry Crist (@rycrist) October 24, 2017

That puts the Echo Plus' sound quality much closer to the Echo than to competitors that put more of an emphasis on pristine audio. Like the Echo, it's perfectly capable of filling a room with good-sounding music, but if you're hoping for a high-fidelity audio experience, you might come away disappointed.

A more noticeable uptick in sound quality would have gone a long way towards helping the Plus live up to its name, but the addition of an aux-out jack renders that point largely moot -- audiophiles probably already have a setup they're happy with, and in most cases, the Echo Plus can pipe music through it.

Zigbee smarts

Ry Crist/CNET

The addition of a Zigbee radio means that the Echo Plus can connect directly with Zigbee gadgets, of which there are many. The most notable name in that mix is Philips Hue -- with the Echo Plus, you can connect with any of the numerous Hue-branded lamps, light bulbs and light strips available and control them right from the Alexa app, no Hue Bridge necessary. That's a tempting way to try out a single bulb before committing to an entire Philips Hue starter kit.

To that end, Amazon is currently offering a free Hue White LED with every Echo Plus, a $15 value. Nice touch.

Still, there's a glaring problem with that integration with Hue, and that's that the Alexa app can't change the color of color-changing bulbs. Alexa can via voice command, but the app itself only lets you turn lights on and off or adjust their brightness. That obviously isn't ideal -- voice commands are great for quick changes, but sometimes, you're going to want to use an app's color selector to dial in on a specific shade.

You could do so easily using the Philips Hue app -- but the app can't connect with the bulbs unless you've got the Hue Bridge plugged into your router. Kind of undercuts the whole point of having an Echo Plus, doesn't it?

That limitation extends to other Zigbee bulbs with multiple color settings, too. For instance, I was able to pair the Echo Plus with a Tradfri smart bulb from Ikea that offers different color temperature settings ranging from warm white to cool daylight. I could adjust the tint of the light using voice commands, but not using the Alexa app. Alexa, add color control to your to-do list.