I use Sencha ExtJS every day.. (now v.6). We still have a few applications with it but have recommended that my clients move to React (for new development). I

I use Sencha ExtJS every day.. (now v.6). We still have a few applications with it but have recommended that my clients move to React (for new development). I have heard a lot of complaints over the years about Ext's complexity and I guess I would have to agree. It's a bit like writing windows code with MFC. Not completely horrible if you know like the entire library, but somewhat daunting at the beginning. The grid control was pretty nice (I think someone commented on that), but the newer component based architectures are much better.