I used the feature for the first time over the weekend, sending the route home from my app to my watch while I was running. It’s a great feature.
Of course, it would be even better if you could actually reroute when your phone is connected.
It would also be handy if, when you leave a route, you automatically get a kind of ruler to the next shortest waypoint. That way, you can see at a glance which direction to take at the next intersection.