We have 5 quarq PM's in the fleet at the moment for the last 4 years. I had one die last fall at the start of CX season, like yours it was 4mo outside warranty, I had to buy a new spider to get it working for my CX races but that's the only issue we've had so far. I know they can't last forever but maybe their purchase of Powertap will give them help reliability wise. Had a Powertab hub that was 6+ years old and still 100% when I sold it.