At least on Android, it "feels" fast enough. However, it breaks navigation when you use the Back button (in the interface) and the Back button (part of Android).
This alone, makes the app clunky.
This alone, makes the app clunky.
On "feeling fast enough", let's pick a jquery mobile case, I tried http://www.jqmgallery.com/2012/02/11/sharksfrenzy/ on galaxy s2 (dual core, etc) and iPhone 4s. The list (notice its translucent, and overly decorated) scrolls like snail on the android phone. While it flows very smoothly on iPhone 4s.
A similar list would do better than that on Android if done in Sencha Touch 2.