I sent an email to Len Gregory "The Cartridge Man" about which cart weights/compliance ranges make the best synergy with his Conductor. His reply was:
My 3 carts are all in the 7-7.5gr range, although the Dyna XV-1s I'm considering is 12gr. Gonna need a different weight for that one.
we make differing counterweights to cope with cartridges weighing anything from 5 grammes to 20 grammes (maybe heavier) and the pump has a built in flow regulator to cope with the extra mass.
My 3 carts are all in the 7-7.5gr range, although the Dyna XV-1s I'm considering is 12gr. Gonna need a different weight for that one.