Works pretty well in areas that have good OSM coverage as well, and it can intelligently follow gpx tracks. The only thing I miss about it is no Apple Watch integration.
Having biked over 2,000 km in Europe and daily commute, I have to say OSM maps are close to being very good. Once Inna while it suggests some path that's clearly not suitable for cycling, but most of the time, the route suggestion takes Euro velo, Dutch cycling routes, etc.
These routes are only as good as the data, but at least in Western Europe, the map data is quite accurate.
