The jeep charges and AT-driving were fun, but required quite a suspension of disbelief.
While a jeep or Kübel might have been (and still be) able to drive so fast on a paved (or sufficiently flat unpaved) road, doing that cross-country or in sand was not realistic by any stretch of imagination. Not to mention that in real life, nobody (outside Japan :p) would have been suicidal enough to pull stunts like that.
APC's were invented for a reason, namely that "soft" vehicles tended to die horribly when they reached the battlefield, so this is one more change that makes the game more realistic. I think that the new speed for wheeled vehicles is fine. It's still much faster than walking/running, but requires you to either bail out early and charge on foot, or take a detour away from known enemy positions.