For reference, I own a lot of power meters. I'm an ultracycling coach, and all of my athletes use power meters as well. I personally own a set of Favero pedals, PowerTap pedals, PowerTap hubs, multiple Quarq Spiders, 4iiii crank PM's, Stages Crank PM's, as well as a Wahoo Kickr and Kickr snap and a 4iiii Flight trainer.I have athletes that had prior versions of the Garmin pedals, that had a LOT of problems. Most were associated with the known battery issues, as well as some issues with power readings (some models were finicky to install). I was a little reluctant originally to purchase the Garmin Rally pedals, based on the feedback/problems experienced with my athletes with those prior versions. I wanted a SPD pedal, and ended up getting a dual side set. I've ... MoreFor reference, I own a lot of power meters. I'm an ultracycling coach, and all of my athletes use power meters as well. I personally own a set of Favero pedals, PowerTap pedals, PowerTap hubs, multiple Quarq Spiders, 4iiii crank PM's, Stages Crank PM's, as well as a Wahoo Kickr and Kickr snap and a 4iiii Flight trainer.I have athletes that had prior versions of the Garmin pedals, that had a LOT of problems. Most were associated with the known battery issues, as well as some issues with power readings (some models were finicky to install). I was a little reluctant originally to purchase the Garmin Rally pedals, based on the feedback/problems experienced with my athletes with those prior versions. I wanted a SPD pedal, and ended up getting a dual side set. I've compared them to several of my other PM's and trainers, and overall, I've been happy with the pedals. One important aspect is that you need make sure the pedals (actually any power pedal... this is true of Favero and PowerTap pedals as well) is firmly installed. If they are not, they are subject to power inaccuracy. I've also lent these out as part of my coaching practice, to help athletes check their power devices and diagnose problems. They are simple to use, and I've found them very reliable overall (e.g. in terms of consistent reading). When I've observed left/right imbalances or data that seems inconsistent, when the athlete firms up the pedals and does a few sprints and recalibrates, they've worked great. I've had no issues with batteries, as was observed with previous versions. My only ding on one star is the price... they are substantially higher cost than the Favero pedals (which are also reliable and accurate, but not SPD), and higher than many spider based systems.For those looking for SPD pedals, I do recommend these overall.

I ordered these pedals with express shipping. They arrived with no batteries. Not sure if batteries were removed in shipping (air) or just misplaced at warehouse. Either way, I had to go out of pocket for batteries and they are exceptionally hard find: 2 weeks later not yet using.I’d recommend pre-buying replacement batteries so they are in hand when they expire. And I’m disappointed batteries were not included in my package.

I ordered a pair of these very early on. The first pair was clearly over-reporting power (20+ watts) and the power was show a large left right imbalance that my Garmin Tacx 2 Trainer says is not real. Garmin support were very helpful, though they did take a week or two to review the data. They decided to send me a new pair. The second pair had similar problems though to a lesser degree. The power was 10+ watts high and there was still a left-right imbalance with other tools tell me does not exist. I got a full refund, but still wasted a lot of time on it. I just wish they had worked out of box. Depending on what I hear in the future I might buy again in a year in the hopes that the engineering/manufacturing problems have been worked out.