Too much rain to do any riding so I am stuck inside using the Bing layer.
I don't know about other places, but here in Korea, although usually having better resolution than Yahoo, it is often out of alignment as much as or worse than Yahoo. And it is usually not a one quick fix solution. Now and then there are alignment errors within one imagery set, occasionally within resolutions in a set, and usually differing alignments between obviously different imagery sets.
Still, having the imagery is certainly better than not having it.