Coros collects Stryd power, pace, and distance data but applies data smoothing to it. For example, the maximum power during a hill sprint could be lower when reported by Coros than by Stryd. In practice, this smoothing does not affect the integrity of your data and will slightly affect your metrics like critical power.

When you run with Coros, and you upload the data from Stryd with the Stryd app on your phone (offline sync), you can compare the data recorded by Coros versus Stryd itself.

The differences will be small but they will be there.