zooming in and out of the map shown on the details view of an activity is a little too sensitive, but still workable.
If you switch to the player view, and do the same scroll wheel action on the map shown there, the results are unexpected and not good. Try a little flick of the scroll wheel, and you are immediately presented with the entire world (shown twice). Another flick of the mouse wheel to zoom back in, and there aren't any images at that resolution. Very carefully click one scroll wheel increment out by one increment out and eventually you find you are somewhere in central africa although you started somewhere else. That's just unusable.