I have a functioning Polar ecosystem: bike computer (V650), fitness watch (m400), chest strap (H7) and even the scale (Polar Balance) …all plays nicely together with no issues.
But the Garmin bike computer are so much better (Edge 1030 or 830) …Ant+ support, active map routing, better display, better everything.
Now, should I get a Garmin bike computer?
…when running I could still use my m400 with the H7. The H7 also works with the Garmin bike computer. I would however need to keep the Polar Flow app as well as installing Garmin Connect app for the new bike computer. That does not worry me too much though, because ultimately what counts is in Strava. I could still syncronize my scale with m400. I would loose Polar flow recovery data coming from all sports activities (running and cycling).