A man with one power meter…
I’ve been down this road, started with a SS Stages, compared to a Kickr v1. I hated the Kickr because it was reading low. Wouldn’t use ERG. Sold my Kickr, tried rollers (not good in a condo with neighbors), bought Garmin Vector dual-sided power pedals, bought a STAC Zero, finally back to a Kickr and using ERG mode.
So in my rabbit trail of pursuing power readings (and significant expense), I discovered I’m left leg dominant, so my Stages was reading high. My v1 Kickr wasn’t all that accurate either, but closer than the Stages. My Garmin pedals read higher than the STAC Zero (it was great but I had to replace the Zero when my next bike came with a through axle) and also a bit higher than the Kickr 2018.
All that to say, I only found peace with this by choosing a “source of truth” for indoor training. Consistency beats accuracy every day. Multiple sources only drove me batty.