I vote keep it. I can't seem to get the zoom levels that I can get on
googles elsewhere. I very often switch between topo and aerial to see
if an ancient trail is still there, or to see if it is overgrown etc.
Maybe a compromise, a small popup disclaimer in the corner of googles
saying that mapping functions are not available on these maps.
Also, have you looked into using microsofts maps? Bing? I think they
are significantly better than googles, at least sharper where I live.
I love this app, it has gotten me to some of the coolest places I have
found.
Thank you for your hard work,
Matt