A stateroom still costs 4 dtons of volume. You can now include things like pools, exercise gyms, galleries, battlesuit morgues, etc direct from GURPS into HIGH GUARD. It will make some of the ships created this way seem less capable than ships built from the HG days, but then again, you're donating space for a galley, gym, morgue, etc that wasn't available for HG. Best of all? You dnn't really have to convert between either of GURPS TRAVELLER for any other traveller for that matter - just use the extra "systems" as if they had been designed for HG from the start.