This a million times. I spent a better part of the last year optimizing the hell out of an HTML5 app and the bottlenecks are almost entirely in initial rendering time (CSS stylesheets and HTML Parsing/Manipulation and coaxing the memory management to not explode on you with a lot of images).
Hi,
Agreed that in your standard app, the overhead of rendering will outweigh that of communication with native code.
For us at Trigger, however, we don't have any control over the efficiency of your Javascript, or the interpreter and rendering engine that holds it.
What we can control is how efficient the communication is between your JS and the underlying native APIs. Everyone agrees that performance is a key issue, so we take great care to ensure that the performance of code we control is as small as possible.