These things are incredibly handy in almost any situation. The truck (PLS) can lower the Mobile Tool Shed (known as a FRS) onto the ground in under a couple minutes, and can be reattached and raised in about the same time. The PLS can also carry crates full of supplies, and can be adapted to fit a variety of roles. The tires feature a run flat system , so it is much more reliable than a track vehicle. It even features a ether cold-start-system that can be used if the vehicle won't start by itself. Also, the armored PLS variant is a juggernaut. One of my friends got hit by a IED in one of those things, and it didn't even make a dent.
The FRS has about every tool you can imagine and has a boom capable of lifting a tank engine with ease. It also features a air tank, Oxygen/Accetalyne Torch, and drop lights along with a auxiliary power unit capable of running pretty much anything you can hook up to it like Laptops, Microwaves, Coffee Makers, etc....
When I saw the first pic I had to post this because it looks pretty similar. The PLS runs off a Detroit Diesel engine, but I am sure a Fallout variant would have some kind of power cell technology. I used to use the PLS all the time in the Army, and I can attest to it's reliability and usefulness. Many of it's uses were unintentional, but very handy nevertheless. We would put 5 gallon jugs of water on the APU when it was running, so we could have hot showers.
Of course it can be outfitted with a turret in the middle, so you can have a gunner equipped with whatever crew served weapon you desire. Anyway, I thought you guys might be interested by this.