Well, they could be driven relatively fast by what I understand. But they were essentially redeployable wooden bunkers, not mobile fighting platforms. By what I know of their size, construction and fighting complement, on the move it must have been pretty cramped in there especially for the weapons the soldiers mostly used (ie. crossbows, firearms, and assorted two-handed ironmongery; the Hussites were notably particular to two-handed flails).

If you need an RTW concept to think of them with think phalanxes or the BI schiltroms, not horse-archers.