I have the Garmin Topo maps and have mixed thoughts…
I really like the terrain features, using the topography to see whats coming up, but and it is a BIG BUT… the topo lines are the same size and colour as the trails, so its hard sometime to distinguish.
Most places I have been, including back of the Blue Mountains, Victorian high country, Snowys, Tasmania and Border Ranges have been on the street maps.
So, I keep them loaded but only turn them on when the terrain is getting a bit lumpy or on private land as the tracks are on the topo’s.
If you get right out and amongst it, get the topos but if you are on fire trails or non single track trails, the street maps are fine and pocket the $200.