I just got through a run of several US M3 half-track derivatives. I can tell you that any single one of them required much more work than a tank subject. The reason is that half-tracks or your Sdkfz 234s with open tops requires practically every single surface to be built and detailed and painted -- unlike the "shell" you'd have to detail and build for say, the Tamiya Hetzer or a Tasca M4A3 tank.
At least this is my theory. For a recovery from my half-tracks, I'm plodding through the Tamiya Matilda -- nice and relatively care-free!