Just found this 'new to me' topo layer for Google Earth. Best I have found so far, minimal delay compared to others, and you can adjust the topo overlay opaqueness with the slider under 'Places' in the left margin to still see the satellite layer.
http://www.metzgerwillard.us/quads/quads.html
http://www.metzgerwillard.us/quads/quads.html