I responsded to your question on the Cynergy below as well ...so I won't duplicate it ...
I have a GraCoil on my Trap gun ( Citori XT with 32" barrels ) - and I've had hydraulic systems ( not Ruckers ) on 2 of my Skeet, Sporting and Hunting O/U's but I thought they delayed the 2nd shot while the system recovered - and I didn't like it / so I re-stocked those guns and started over....and returned them to standard recoil pads.
The GraCoil doesn't bother me on Trap / because there is less left to right barrel movement on the 2nd shots ... but I couldn't get used to it for Sporting, Skeet or for hunting ...