Best thing would be to try it out. - availability of zoom levels depends on the server (terraserver-usa responds to most of them - others only to certain levels) - file sizes are more in the range of satellite maps (as lots of maps seem to be hand drawn, compression doesn't work that well - may be the image/jpeg format leads to smaller files) - currently the most annoying thing is the terraserver-usa behaviour - may be it's possible to add some pauses, when downloading? - 'proj' should be ready for installation (no graphics!) Hiking in the Bavarian Alps with these maps worked fine for me!