When comparing Google Hangouts vs Element (formerly Riot), the Slant community recommends Element (formerly Riot) for most people. In the question“What is the best voice chat for gaming?” Element (formerly Riot) is ranked 3rd while Google Hangouts is ranked 8th. The most important reason people chose Element (formerly Riot) is:
You're not confined within Element's or even Matrix garden, and you don't have to make users of other networks switch to Matrix.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Mobile support
Hangouts offers both an Android and iOS app so users can participate from nearly any mobile device in addition to his Desktop.
Pro Screen sharing
Any user can share his screen (or only a specific desktop or window) while still continuing an audio conversation.
Pro Free group video support
Hangouts works with up to 10 participants using video out of the box or up to 15 if you are a business, government or school. It determines who is the primary speaker at any given time, and the camera view automatically switches to that user.
Pro Useful for businesses
Hangouts can scale to become a videoconferencing solution for an entire company, since the software can run on nearly all platforms. In fact, Google itself uses Hangouts as its meeting room video conference software.
Pro Easy to start using
Hangouts is integrated with Gmail & Google+, does not require you to download desktop software, and all chats can take place directly in your browser, significantly reducing the barrier to entry for a new user.
Pro Completely free
Google offers all features of Hangouts completely free. There are business, education and government solutions that increase the participant count to for video calls to 15 and offers support.
Pro Cross platform
Hangouts work on Android, iOS, Chrome OS, web and as a Chrome extension.
Pro Live broadcasting and instant recording
With Google+ “Hangouts on Air”, you can broadcast any hangout to an unlimited audience via your Goolge+ Profile or simply a generic YouTube link. Moreover, any Hangout on Air (public or private) is automatically saved as YouTube video that you can keep for private reference or use in any way that you would normally share a YouTube video. This allows you to record conversations without additional obtrusive software.
Pro Google Voice integration
Allows for a fixed phone number, receiving and making calls. Calling US or Canada is free.
Pro Integrates with Google Maps for sharing locations
When chatting with people while trying to plan a meet up, the share map button can be extremely useful.
Pro Android app does both sms and hangouts messaging
Pro Bridges to other networks
You're not confined within Element's or even Matrix garden, and you don't have to make users of other networks switch to Matrix.
Pro Markdown support
Code snippets in chats can be highlighted with Markdown.
Pro Simple interface
Element has a very simple interface, adding the ability for more inexperienced users to use it.
Pro VOIP and Videoconferencing
Pro Supports encryption
Element allows for fully encrypted text, voice, and video chatting.
Pro Widgets support
Want to watch that flick at YouTube and discuss it at the same time? Have Grafana graphs stacked above your DevOps team chat? Collaboratively edit Google Docs and chat over without switching applications? This is possible with Element.
Pro Decentralized
An open network for secure, decentralized communication.
Pro Self-hosting and federated network
Pro Libre/open source
Pro Search
Search messages in your current room, or all the rooms you're in. Not subject to a message history limit like Slack.
Pro Cross platform
Web browser
Linux
OS X
Windows
Android
iOS
Pro Large existing community
With public rooms for many people, and you can create your own and let people from the community join.
Pro Etherpad real-time document collaboration
An easy to activate integration that allows multiple authors to edit a document simultaneously.
Pro File Sharing
Pro Supports text, voice, video
Cons
Con Poor video call quality
Only goes up to 720p30 + low bitrate.
Con Owned by Google
Con Lacking clients for older versions
Con High hardware usage
Con Not recommended for long sessions

Con Won't work on Windows 8-style UI
As Hangouts uses a browser plugin on the desktop and it doesn't work with Windows 8-style UI, it has to be used in desktop mode.
