To me the most impressive thing is that Sencha Touch can run at any reasonable performance level. Has anyone used the framework? iirc there's >1mb debug JS, randomly-generated element IDs, a mess in general. The thing would hang my chrome for a couple moments just to parse the js. Obviously this is solved with minification/dynamic script loading, but Sencha's kitchen-sink approach really doesn't seem to help much in the area of performance.
You're supposed to use the build tools to generate a file with only the subset you need for your project.
By the way, the download time for the native app is also non-zero. With appcache you pay the framework's download cost only once. Admittedly it still needs parsing to load, but i haven't had this seconds-long parsing experience myself in my sencha touch app.
> You're supposed to use the build tools to generate a file with only the subset you need for your project.
Both Ext and Sencha Touch are very monolithic. When you use Sencha Command to pair your app down to just what it uses, it still pulls in well over 90% of the framework.