I just finished my first ride where I did not have issues with the groupset. For anyone with an ERX / ER9 groupset, I suggest you add some ductape between the connectors for both derailleurs. After I did this, the groupset has been incredible, and is a dream to work with. Especially for that price (~500 eur).
The groupset is not able to withstand any type of moisture, but thankfully ductape does work.