While most riders are usually just out for an afternoon ride, some riders are looking to escape for a little longer. These riders are looking to go for exploring for a weekend or even longer, and that requires a little more preparation. It means a lot more equipment must be taken onto the trail, as well as food. While most of that can be carried in saddlebags and even a backpack, the one item that needs to be debated is the bed roll, as it has most of the bulk of the equipment carried onto the trail. The saddleback bed roll is that best solution, as it allows for a lot of the problems facing riders on long trips.
The biggest problem is that a bedroll has to be both light and and warm, as well as relatively durable. This is an important issue as the bedroll must be thick enough to keep the person warm enough at night but light enough that it can be carried by the horse without a major encumbrance issue; the horse is carrying all of the equipment and food, after all, so weight must be kept to a minimum. It also needs to be thin so that it can be carried without catching against foliage and causing the horse to be slowed down or even caught in the foliage. That is, a bedroll cannot slow down the horse, and a thin, lightweight roll is far better than a thick, heavy one.
The bedroll also needs to be warm at night. While most modern materials for sleeping bags fortunately squeeze down to a reasonably small volume, they are not always warm. The best bedrolls are more insulating than warmth-causing, meaning that they keep the warmth in and allow that extra warmth to keep the person warm throughout the night. The mummy bag is probably the best, as it limits the heat escaping while allowing for the smallest possible volume while stored. Again, this is great for those on horseback as it means that the bedroll is both light and warm.
All of these features have been combined into the saddleback bedroll. This allows the rider to carry as much food and survival equipment without having too much about the bedroll. This allows the rider to spend less time on foraging and more time exploring and taking pictures, which is the focus of the trip making for a more memorable trip, as well as more time for the horse to rest. Thus, by making one item lighter and better, the rider is better able to focus in on escaping, which is the reason for riding off into the sunset in the first place.