How would this into the environment or scenario, how would it be impressive? how would it help gameplay? all I've heard so far is that we need a speedy engineer, for late game building of the base (because you can't at the start because you don't have a VF) so instead of getting someone to come back to the base to build the base, you get someone to come back, spend 400 odd on a vehicle, build the base, and then get out and leave the vehicle to rot somewhere. because the vehicle is a huge target for arty, it won't be useful when you're getting seiged. what's the point!
In early game it of course also protects versus gunfire, of course. I reckon it will also move faster then a sprinting Scout. I doubt anyone will leave it behind, because you ALWAYS need to build something.