No experience with the Canadian M101, but I've had a Vietnam era M416 since about 1994. The M101 is basically a modern upgrade of the M416. If you can find one go for it. They are light, tough and will haul a lot of weight. I keep kicking around fabricating a top cover with lift cylinders and maybe shelling out the big bucks for one of those African car-top tents...but I never get around to it.
Here is a shot from a 2006 trip to Mexico.