Is there a tipping point where the increased multimedia power of flash overpowers the accessibility of javascript? We're powering though some pretty serious tec

Is there a tipping point where the increased multimedia power of flash overpowers the accessibility of javascript? We're powering though some pretty serious technical hurdles to get what we're working (which has highly graphical components) on running in pure javascript. Seeing what Heroku has done has encouraged us to keep going, but we wonder if picking pure javascript really was the wisest choice.