When comparing Messenger vs Trillian for Business, the Slant community recommends Trillian for Business for most people. In the question“What is the best team chat software?” Trillian for Business is ranked 24th while Messenger is ranked 74th. The most important reason people chose Trillian for Business is:
Trillian seems serious about security and privacy, and is ready to explain in detail how they architect their service to achieve these goals.
Specs
Ranked in these QuestionsQuestion Ranking
Pros

Pro Uses Facebook friends to create a contacts list
Allows communicating with anyone who's a friend on Facebook.
Pro Read receipts
Can see who has seen each message in group messages.
Pro Easy to share posts from Facebook
Integration with Facebook makes it easy to share any interesting posts from the Facebook timeline.
Pro Great UI
User interface of the application is clean, intuitive and easy to overview.
Pro Comprehensive security and privacy policy
Trillian seems serious about security and privacy, and is ready to explain in detail how they architect their service to achieve these goals.
Pro Self-Hosting available
If you are worried about third-parties getting access to your data you should consider self-hosting. With self-hosting you are in control over where your data is stored, who has access to it. You will also not be vulnerable to exploits of a third-party provider. Trillian supports both cloud hosting and a self-hosted Trillian Server.
Pro Native clients for Windows, Mac, Linux, iOS, Android, and Web.
Trillian has fully native apps for Windows, Mac, Linux, iOS, Android, and Web.
Pro Multi-protocol support
Chat with other Trillian users or those on Facebook, Google, AIM, ICQ, XMPP, Yahoo!, Twitter, and more.
Cons
Con Lack of privacy
Messenger is owned by Facebook. Based on their privacy policy, this means that any information you provide (including messages sent) are used by Facebook to profile you and sell access to your data to advertisers.
Con Lack of end-to-end encryption
Secret (end-to-end encrypted) chats are only supported in one-to-one messages, and are not enabled by default, and the encryption has not been verified independently.
