Replaced a Power2Max with these pedals, which will move between bikes. They are nearly dead on accurate with the Power2Max and my Tacx Neo trainer, so I can vouch for accuracy of watts.
I like the ability to see where my power is on the stroke and where it is off or needs work. I also like the pedal offset metrics and am trying to dial in the cant of the clips to have better power applied to the center of the pedal....can do that with Power2Max.
After switching to a shorter crank arm on my Tri bike, ( a 155 length) I could no longer use my Stages power meter as they don't have a version to fit a 155 crank arm. I ended up looking at the Garmin Vector and the Powertap. I chose the Powertap for ease of installation. It worked right away and install was really simple. Definitely a good choice for me. I only use the left side power, not both sides, which makes it similar to the Stages I was using previously.
I have had these pedals since November '2015. I have used them primarily on my trainer bike but have ridden them outside. NO CONCERN with durability. They were easy to set up and I recently transferred them to another bike and it was very easy. I love the data that I get and have increased my Average Normalized Power as a result. Would buy another pair if I could afford it )!!!!!
I have been riding with the Pioneer left side for couple of months now and it has worked perfectly. I have had zero issues with calibration, connections to my Garmin Edge 1000, or connections to my PC based ANT I use for inside training rides. So far I haven't noticed any significant differences in power readings between my bikes that have Stages PMs but I haven't really studied the data closely. The Pioneer factory warranty is 2 years vs 1 year for Stages. Round trip from Portland, OR to San Diego to get the PM installed on my left crank arm was 7 working days.