Personally I think my Stryd is far more accurate and repeatable than any other pod I’ve tried. I’d give the Garmin foot pod 2nd place (foot pod, not dynamics pod) followed by milestone.
One bummer about milestone (Zwift pod) is that it’s BLE only so can’t record with a phone and Garmin at the same time (and even separately the old Garmin devices without BLE sensor support can’t use it).
At one point the milestone pod tried to offer some impact analysis / efficiency charts but if I recall correctly Zwift killed that app and support after the acquisition. It was probably not real useful anyway.