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.
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.
Sencha Touch is targeted towards enterprise-level development, and the price tag reflects that. There are many different product options available by Sencha. Most licenses start in the thousands of dollars, and require a minimum purchase of 5.