Portal can call anyone with Facebook Messenger, which likely is most people you know. That's a major strength of the device over its competitors. For example, the Echo Show and Echo Spot are limited to calling other Show and Spot users or folks who use the Alexa app and the Lenovo Smart Display is limited to calling users of Google Duo.
Additionally, at $199, the 10-inch Portal is more competitively priced than its peers. The 10-inch Echo Show sells for $229.99 while the 10-inch Lenovo Smart Display is priced at $249.99.
Aside from video, both Portals feature everything else you'd expect from a smart speaker. The devices can stream music from Spotify, Pandora and Amazon Music, and they are enabled with the Alexa assistant, giving Portal users access to the many skills available on Amazon's service. I found audio over a video call to be a tad underwhelming, but once music started playing, the sound was perfectly crisp.