Do we know what's different? From the panda podium video I didn't understand what changed with the new erx (with the exception of the brakes but i don't think anyone had any issue with the brakes, I certainly didn't).
Hopefully they improved the mechanic design as well as the water protection .....
I was just thinking about your rear derailleur failure description (the one failing after some tough decent) if it's a smart idea to ride something similar on a MTB with all that mechanic shocks.
I don't think so frankly. If there's a general design flaw this kind of sickness usually gets the whole " product family".