When comparing Xamarin vs Ionic Framework, the Slant community recommends Xamarin for most people. In the question“What are the best frameworks for developing cross-platform mobile apps?” Xamarin is ranked 2nd while Ionic Framework is ranked 5th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Xamarin Insights and Test Cloud increase user experience
Pro Cross-platform
Apps built with Xamarin can run natively on Android, iOS and Windows Mobile. Xamarin compiles the same C# or F# codebase to native code that runs on several platforms.
Pro Open source
The Xamarin SDK is free and open source and released under the MIT license.
Pro Cordova plugins
Large quantity of plugins to access native APIs without code nothing in native language.
Pro Large, friendly and active community
Ionic Framework is currently one of the most popular frameworks for hybrid mobile app development. This has resulted in a very large community of active users who contribute to the community by writing tutorials and answering questions.
Pro Free and open source
Ionic is free to use and open source, resulting in an active and helpful community of users and contributors.
Cons
Con Build time tends to be longer than Android Studio
Con Slow to implement new features; must wait 1+ month to be able to access it
Con UI editing and creation is unstable
Con Can be buggy
Ionic is still a young framework (version 1.0 was released in May 2015). There are still some quirks and bugs in the framework to work out, which you can see a list of on their Github.
However Ionic is under active development and bugs are generally addressed quickly.