Ranked in these QuestionsQuestion Ranking
Pro Allows you to develop native apps
Pro Backed by Facebook
Facebook writes their mobile apps in React Native so the code base gets pretty thoroughly used in some highly demanding scenarios.
Pro More predictable control of the state
The one way data flow, makes it more predictable and easy to control.
Pro Native feel
Sencha Touch is well known for its ability to provide a native app experience through it's native-like themes and widgets.
Con Steep learning curve
Con If core team doesn't use a certain feature, it's not developed
Whenever there's functionality you need that they don't use in their apps, it's not going to get developed by them, even if it's obvious it should be in the core. They always say to either submit a PR or create a separate module.
Con Commercial and expensive
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.