* Scrolling needs some serious tweaking, specifically for android. There is a huge time lag while scrolling through a list. * Lacks full access to native hardware, but if you want access to more hardware then you will have to combine your sencha application with PhoneGap. * No support for blackberry. The sencha sdk beta tools provide support for native packaging for only android and iOS (even their team says they haven't tested much on blackberry). * It's still in its developing phase and may take a while for it to fully mature. * Animations run slower. * No support for windows phone as well.
