Feck,
If you're referring to the Canadian topo maps for the Garmin, they're based on 1:50,000 NTS maps, which sadly are becoming obsolete. If you're a geography whore like me then you probably have a stack of these maps stored away somewhere. I used to use them for choosing prime locations for picking pine mushrooms.
I've used the Garmin Canada topo data for wildlife surveys and have relied on an accurate representation of mainline logging roads, waterbodies, and contours to show up where they should to aid in navigation. It's been useful for my purposes.
Send me an email if you want more info or some sample data.
cloudraker@hotmail.com