... "Missing Right Pedal" issue...
Is this just a bug in the head unit or really in the pedals?
For reference, my PT p1 usually give this error as well, but it is fake, an artifact. The power reads just from both, evidenced by variable power balance. It's annoying, but a functionally a non-issue.
There's an issue with head units where the right pedal doesn't wake up as quickly the left after going to sleep, and you'll get this error even though the right pedal wakes up immediately after. But you'll also get this message if the right pedal is dropping out or not functioning at all, which is what many Vector 3 users are seeing.
I'm in the same boat as other (former) vector 3 users, currently going through RMA process with my vectors not only due to battery door issues, but also seeing my left pedal grossly under-estimate power on some rides (to the point where avg balance is 40/60 or lower, even though my true balance is pretty consistently 52/48 give or take a percent).
I just purchased the Assioma Duo's, only have one ride on them so far but they seem to be working. Setting aside PM functionality, I think the vectors are better pedals (better clip-in/out), but so far I'm reasonably happy with the Duo's. I do wish they didn't have those constantly-blinking lights on them though. On the plus side I definitely prefer using a hex-wrench over the pedal wrench required with Vectors.
I'm not sure how I feel about the rechargeable batteries. On the one hand it sidesteps the potential battery cap issues seen not only with Garmin but also early PowerTap P1's. The downside is that if your batteries are low/dead your only option is to plug-in and wait. With a replaceable battery, you can do a quick swap and go about your ride. I'm thinking I should probably order spare charging cables just because it would suck to misplace them or realize you left them in your other bag and can't charge.