Nothing personal m8t's but the US tank destroyers are well collectively ahhh krap....
They all sacrifice armor for speed and with the exception of the 90mm tube on some late war models armed with a gun that could only be described as moderately effective against German tanks, and less than effective against most all late model German Tank destroyers.
The whole concept behind US tank destroyers proved to be a bit flawed,especially when compared to the way the Germans and Russians built them and deployed them.
Another annoying little aspect of them is that they are open toped,everybody and his grandma with a rock in her hand can hurt/stun/kill the crew with relative ease.
Yes speed is nice but they are, I feel, better choices for speed and a medium armament,say a M-24, a Puma,AEC MK 3,Daimler, to name but a few.
You will have to forgive my impassioned distaste for US tank destroyers for I am a Veteran of many an hour playing Advanced Squad Leader, and they gave me many a headache.
Brady