Hydraulics with accumulators is technically a hydro-pnuematic suspension as the accumulator is charged with a nitrogen bladder which absorbs the energy when you hit a bump using the cylinder as a shock itself. You can tune the ride on your hydraulics in 2 ways: 1) You can have your accumulator charged at a higher PSI which will eliminate the sponge out of it, or 2) You can run 4 flow control valves adjacent to the accumulator which you can manually "tune" the firmness of your ride. This is heavily done in Japan by the Skipper style hydraulic setups (
www.skipper.co.jp). This is a $143.00 Hydroholics option that we offer.