I am looking at doing some photo sims for a cell tower company but need a good Mac topo program. They pretty much use Delorme Topo USA. I would hate to install XP on my Mac Pro if I didn't have to.
It's worth noting that the Nat Geo software Topo! (4.5.0) is bug-ridden and unstable. It works, but just barely.
Add to that a mind-bendingly bad UI that is so counter-intuitive I find myself referring to the (grossly inadequate) manual for things like erasing something I just drew.
My guess is they outsourced this to a Windows house with zero experience with either the Mac or mapping software. Good Mac apps don't bury functions under right-click contextual menus, to name just one bad decision.
The maps themselves, on the other hand, are gorgeous.