Is the difference worth over twice as much?
That Q cannot be answered as it is an individual thing, but I now have 2 x A20 and 2 x X, have been flying with the Xs for 10 years and with the A20s for 6-12 months, and the A20s are very noticeably better than the Xs.
When I first flew with the A20 I was a bit worried that the engine did not sound like it was making much power
So I checked the gauges etc... all was fine.
The A20 really is the best headset out there.
The price is just silly. Bose are minting it of course. You can buy them in the USA for less but not by the time you pay VAT and shipping etc.