This is not a question that can be answered by us. You already give a solid overview for your team (which is all that matters):
Same
- rich controls
ExtJS Pros
- more widget components
- scheduler control
ExtJS cons
- Sencha does not make its source code available on GitHub for pull requests
- There is no public issue tracker
KendoUI Pros
- faster (I’m not so sure about that)
- no learning curve
- jQuery community support
- Material Design theme
KendoUI Cons
- smaller set of widgets in the open source Kendo UI Core (grid, charts are in the Professional version)
- no Architect
I’m sure an application can be built with both frameworks. What’s more important to you? Fast delivery (you say that your developers can jump right in with KendoUI), or strategic orientation for the future?
That being said, we are developing with ExtJS. We are generally satisfied, with some caveats:
- The documentation is often outdated or incomplete (that’s improving with recently introduced community comments)
- It not trivial to expand the functionality of some built-in widgets