The problem lies in how it is used. Our project tried to incorporate a ton of native UI/UX conventions that screwed us over royally. CSS transitions, layered divs, swipe gestures, all of these were far too complicated for a little phone to handle. Stay away from these, and do simple hides and shows. Or go the hybrid method of having barebones native wrappers and web-views inside of those views.
The web (i.e. HTML/CSS/JS) promises a lot but mobile browsers are nowhere near where they should be in terms of pure processing power. As of right now, native is still the way to go.