I also got the cdn tire model, (came with the $10 topo usa and the wall free charger offer) the base map is very sparse but it seemed to be accurate.
I picked up a topo canada and found it really accurate even on recent ski trip to tremblant. But I did unfortunitly pick up the map for the older model (not for explorist -doh!- but it still works don't know why ) the problem i find with loading info to and from comp using the old topo software is you have to save it then transfer using the map lite software because the topo canada software goes looking for the com ports instead of the usb connection.
-the topo can indicate transmission line when driving along, you look up and theres a transmision line, kinda cool.
Tough time getting accessories for it though, had to get them from the dreaded evilbay.