The Good: The Google Assistant-enabled JBL Link 20 has Google Chromecast built in and can be linked to other Link and Chromecast speakers to create a multiroom set-up. It delivers strong sound for a portable speaker, is fully waterproof, and has both Wi-Fi and Bluetooth. The Bad: Slow start-up time; some distortion at higher volumes. The Bottom Line: Among the handful of voice-enabled portable Wi-Fi speakers out there, the JBL Link 20 is arguably the best for the money. One of the great things about both the Google Assistant and Amazon Alexa voice-assistant platforms is that they're both very open. It's easy for third-party companies to make compatible smart home devices that work with both of them. In fact, companies can also make their own smart speakers to compete directly with those manufactured by Google and Amazon.One of the latest companies to take up the Google Assistant smart speaker mantle is JBL, which released a new line of voice-enabled speakers in late 2017 under its new Link sub-brand. The line features a combination of two fully waterproof battery-powered portable speakers -- the JBL Link 10 ($150) and Link 20 ($200) -- as well as two AC-only models, the Link 300 ($250) and Link 500 ($400). The upcoming Link View, meanwhile, is one of a new wave of Google Assistant devices with a screen built into it.In addition to using Google Assistant for its voice commands, all Link speakers are equipped with Google Chromecast, which enables them to join up not only with other Link speakers but any Chromecast-based audio device to create a multiroom audio setup over a Wi-Fi network. (All Android apps and many iOS apps can send audio to Chromecast speakers at the touch of a button.) The speakers are also equipped with Bluetooth, which offers universal compatibility. The Link 10 and Link 20 look like bulkier cousins to JBL's cylindrical portable Bluetooth speakers. In fact, from a sound quality standpoint, the smaller Link 10 is in the same ballpark as the JBL Flip 4 and has a rated battery life of 5 hours via a Wi-Fi network. It's a decent portable speaker but the Link 20 (reviewed here) is really the one you want. Not only does it offer fuller sound with better bass, but it has twice the battery life for $50 more. It's arguably the best sounding portable voice-enabled speaker at the time this was published, but the competition is pretty limited, with the UE Blast and Megablast being among the only serious adversaries along with the Amazon Tap (all three of which use Alexa, not Google Assistant).Setting up the speaker is relatively simple via the Google Home app on iOS and Android devices. You log into the speaker using a direct Wi-Fi connection, then log onto your chosen network to get the speaker on the network. You can then give it a label for a particular room and link it with other Chromecast-enabled speakers if you have them.The biggest issue I encountered was the speaker's sluggish startup time. Once you power it on, it takes a good 10 to 20 seconds to connect to your wireless network and ready itself to receive voice commands. AC powered models like the Link 300 and Link 500 are always on (like an Amazon Echo) and don't have those startup delays.It'd also be nice if the speaker had a dock option like the UE Blast, Megablast and Amazon Tap. It's not an essential feature, but every time you want to charge the speaker you have to uncover the micro USB port (there's a gasket that covers it) and plug in a USB cable. For those using the speaker at home a lot, the docking station is a convenient feature. The Link 20 has two microphones at the top along with some physical buttons, including volume controls. You can access Google Assistant by pressing the middle button on top of the speaker and issue commands without having to say "Hey Google" or "OK Google" first.Alternatively, you can call out to the speaker with "Hey Google" and a set of LEDs, which also double as the battery-life indicator, lights up to tell you that speaker is ready to take your command. Thanks to the dual mics, I had no problem issuing commands from several feet away (across a medium-size room) in a normal voice. If the speaker is playing music at higher volumes, you will have to raise your voice for it to hear you over the music.