Not head the CDX2 but I was fortunate to get some personal service and demoing when I popped into Rayleigh Hifi in Chelmsford Recently. The Manager was very happy to show me the HDX in full usage and I got to hear about 10 tracks. It was paired with the Supernait and some other boxes (PSUs?) and some £2k Totems.
Well, the sound was amazing. So clear, open and without colour. I also noticed that the beyond the insight and detail was a real notable musical beat and tunefullness. I was hooked! Pair this with the ease of use and fantastic technology its the perfect package but as JD said.....£4500!!!! WOW!
I think they do a version with no screen for £3000?
Sorry that doesnt answer your question
The manager did say its as good as any Naim CD player and potentially better - but this isnt fist hand experience...