I asked him about an reliability update and iirc he said he would try (something like that..), that was months ago, well before the launch of the AXA series. In any case, anything newer than the RX-AX070 likely don't have enough data for another couple of years.
If I were to bet, I would bet Yamaha is more reliable than Denon and Denon would more reliable than Marantz (only because it doesn't have the HDAMs
. To me, from engineering stand point, those units are all comparable in terms of parts count, quality/specs and usage, so I bet Yamaha will be better in reliability because they run cooler. If that is the case, have them running cooler would be a wise trade off, because THD of both are low enough that the differences would only matter to those with golden ears, and/or crazy people/engineer type? like me, who just have to get the one with the better measurements regardless.
D+M's run warmer, an indication of higher bias, so possibly lower distortions as a result. In order to have the Denon/Marantz as reliable one can use an external fan or two.