I've run my Tacoma off-road through some pretty jarring terrain for about a year now with a Z2 installed. Some hard enough to make me wonder if my spine cracked. It finally started to act up about two months ago, and I upgraded the drive to the Z3 with more space. Haven't had any problems yet to speak of with the new one. Obviously as mentioned above, it wasn't really designed for that kind of punishment. Everyone running high-end pre-punners pretty much goes with Lowrance. However, it still puts up with A LOT of punishment.
Most if not all of the roads in the forest around here show up on the maps so I haven't experimented with the bread crumb feature much. Sounds like something to experiment with this weekend.