[bla2]

It means javascript execution is slower in 3rd-party browsers. They can make up for that by e.g. using better networking libraries: http://www.guypo.com/mobile/ios-browsers-speed-bakeoff/

[sspiff]

That still means it's a very asymmetric competition: by default, Apple has a significant head start because of the JIT.

If others have to do some crazy engineering on networking libraries, nothing stops Apple from reusing the concepts the competition implements.

The competition does not have this possibility with javascript engine improvements.

[bla2]

No argument here. Just saying that performance is about more than js performance.