can you give some insight as to what specific issue you were having?
Was it HTML5 that was the real culprit? Or javascript performance? Did you try smaller javascript libraries, etc. etc.
PhoneGap reminds me of the anecdote about a carpenter that sands the back of a bookshelf, "why do that" he gets asked, "no one will see it" and his response is "but I will." That's how I feel developing a phonegap app -- most people don't see the partially finished app; but I do.