
while the zoom slider works well for zooming in (> 100%) it's nearly impossible to dose the tracker for zooming out (< 100%).
Just try 'MinZoomLevel="0.05" MaxZoomLevel="20"' (zooms 20x in both directions, up and down): 100% is nearly at the bottom but I would expect it to be centered.
Additionally a GoogleEarth like slider which just controls the zoom-in/out-speed while being dragged (and snapping back to center after drag) would be also very cool and handy.