Should I update Ayre QB9 dac

After waiting more than a year to have my dac upgraded I've learned that the QB9 is now discontinued. I've owned and enjoyed the dac since it first came out and have had no problems. The upgrade was supposed to be a major improvement and would cost $750. However now that new models are out I'm having second thoughts wondering if the new Dacs have improved technology that would blow the QB9 away.
So has anyone heard the QB9 and the Codex or have an opinion or have an opinion on going ahead with the upgrade?