In reply to:

I think anything in Java is always going to run slower.


Not necessarily, actually -- Because of the Hotspot engine, it is technically possible to have a dynamic optimization of your code applied based on runtime characteristics that could never be determined statically such that sections of your code might actually run faster in Java. Whether this happens in real life or not is sort of hard to know, though. In general, user interfaces in Java do tend to be (or feel) slower than their native counterparts.