I recently bought the Garmin Topo Canada software for my eTrex Venture HC, even though a search on Garmin's site did not list it as compatible software.
I found it worked exactly like the Garmin US Topo (more on this) and loaded on the eTrex without any problems.
The Canada Topo does a nice job listing all major and minor roads, streams, mountains, and hiking paths in SW Canada (my favorite area). I was also pleased with the high road detail in Banff, Lake Louise, Calgary, etc. Oddly, it did not list the famous "tea houses" above Lake Louise, though it did list the paths leading to them. It also omitted the famous Prince of Wales hotel at Waterton and the paint pots above Johnston Canyon.
Garmin still resists updating their incredibly clunky software. Instead of a single DVD, Garmin still ships four CD's requiring switching out disks to load maps, a real chore when your path leads between map sections. Plus the software still operates like it did under Windows 95! Slow, awkward, expensive and clunky, but it does work.