When comparing Messenger vs SeriesGuide, the Slant community recommends Messenger for most people. In the question“What are the best Material Design apps?” Messenger is ranked 22nd while SeriesGuide is ranked 64th. The most important reason people chose Messenger is:
Allows communicating with anyone who's a friend on Facebook.
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 Check In and share
Check in to shows or movies (yes, even at the theater) you are watching and even share the information with social media such as Google+, Facebook and Twitter if you like.
Pro Progress indicators
Information available for unseen episodes and viewing statistics.
Pro Find new shows and movies
SeriesGuide provides access to tract's currently trending shows and finding shows is facilitated through trackt's database which composites information from several main sources (i.e. IMDb, TVDb, TMDb). Also visible are trackt's recomendations and your personal trakt library.
Pro In-app links to common source video data sites
IMDb - Internet Movie Database
TVDb - The TV Database
TMDb - The Movie Database
Pro Third-party extensions available for episode actions
Pro Updated information is synced to trakt
Pro Open Source
Licensed under the Apache License, Version 2.0
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.
Con Pay for advanced features
Pay either yearly subscription or one time for X Pass.
