My number came up in the queue, and I've got my KX-5, VX-5, AND (just by coincidence!) my QB-9 is up for the upgrade too. All of them are being upgraded now, excited to hear the difference! Hard to A/B the difference when so much is changing and a month between listening or so.
For me, reducing the heat in the VX-5 is important, and I did notice that some dc from the preamp was 'leaking' into the VX-5 when changing volume at high levels. No signal needed, something inherently in the switching. I'd never listen that loud anyway, just came across it by coincidence. Looks like they've updated that as well (though it could've been just my unit, dealer said he didn't find the same thing).
Anyway, happy times, totally love my Ayre gear and it's just about to get better