Personally I prefer having a vehicle crew that is always with your vehicle. In this case, your echolon troop can cap or plant demos or whatever. You don't need a rear echolon squad to survive to be able to repair, that is a huuuuuuge advantage over other factions. I find myself often spending nearly 400 additional manpower or even more with other factions, simply to have a unit to repair 1 vehicle. Not to mention it saves time.
It is an advantage but not necessarily a "huuuuuuge" advantage. First you have to keep the weaker units alive and do it while mircoing more of them. If you spent mp on more units to repair that is only wasted if those units can't do anything else. with your increased micro time they could build you some wire, lay a mine, etc.
Also, I don't quite understand how you need more micro to repair vehicles as USF than as Ostheer or Soviets. You just reverse them out and order them to decrew. Once your vehicle is repaired, you recrew and you are good to go again. That is so damn easy.
"more micro" is not so easy. There is a LOT more micro and no shift clicking with USF crews. They don't automatically recrew when done, and they might run off to repair something else. They are also exposed and vulnerable (along with whatever veterancy they have gained). It takes more time to learn, to develop the muscle memory.
Is it better at high levels of play? Perhaps. I will never know.
I don't get to play much and COH2 and Rome II are the only new games I have bought in the last couple of years. COH1 had replaced my love for Total War as soon as I bought it. I even deleted Rome II because it was bad and I prefer to play against real people. But after the last patch I am convinced that Relic's vision for the factions implies that they cannot balance the factions. They are so enamored with "difference" that they don't realize a few similarities won't make the factions ever feel the same. (US is not allowed to have good AT except Jacksons, Soviets never had infantry that knew how to fight. But of course the Axis were all ubermentschen and their war machines so superior you wonder if they can go toe to toe today with an M-1 Abrams.)
Last night I deleted COH2 and reloaded Rome II on both of my machines. I want to like COH2 but can't. I would prefer to wait for the few COH1 games I get than play any COH2.