I have noticed that the stages power meter does not seem to handle large amounts of power or cadence very well. For measured efforts it seems fine, but if I trying going fast, it seems to lose a bit. I also noticed that it seemed worse on the rollers during high RPM efforts. Rapid pace changes or high RPM work seem to throw it off more than my powertap, but I don't have enough meaningful data yet.
I am getting good data that it is useful for pursuit level efforts. I am hopeful to get a session at the track tomorrow to test out some more high RPM/power efforts.