My first PM was Garmin Vector 2 then I switched to Stages Duraace which felt like it was measuring way less in the same rides. I've never stopped training and within few months of switching to Stages I still wasn't able to produce some watt averages of the Vector 2's. Then I switched to Quarq recently and it felt pretty much on part with Stages.
Here are the two readings I got on the same ride. GPS and barometer of the units seem to be a little different hence the different results in distance.
Bottom line, I'm still a weak noob and I'll stick to the same power meter from now on so I can have a better understanding if I'm improving or not

Garmin 510 + Quarq DZero

Garmin 520 + Garmin Vector 2
