I've found CX cabin crews to be quite good and consistent in general. I'd say KE crews in F are a bit more attentive than CX crews (in J or PE), but I've never flown CX F so I can't compare directly.

I've only had one occasion when I had to wait more than a minute or so after pressing the call button. And the FA apologized for the delay.

That said, I do find that CX crews provide markedly better service if you're OWE or equivalent. No status pax will definitely get less attentive service. Which isn't a bad thing, imo...

I am a bit mystified by the JAL comparison. I've found JAL crews to be less consistent overall and far less likely to have any English speakers on non-Anglo routes. In contrast, I've never flown a CX route that did not have at least one English speaking FA.