I only have a Dutch army knife, which is a military version of the Dual Pro X. It has two one hand opening blades with the hole in the blade. This makes it a bit wider than the Parachutist, but it makes opening the belt cutter a bit easier. Also, on the Dual Pro X, the belt cutter is a locking blade. If I am correct, the belt cutter on the Parachutist is not locking. I think these are the major differences. If you think you'll be using the belt cutter often, the Dual Pro X may be more convenient.
I think znapschatz has a good point. For a parachustist, but also emergency workers, the Dual Pro X would be more useful than the Parachutist, because of having a one hand opening belt cutter, which is sometimes also called a rescue blade.