Reservoir shocks are generally thought to be better, with the Nitrogen gas separated from the oil, they can’t mix and this creates more uniform dampening characteristics. The gas is necessary in all shocks to displace the space that the shaft takes up as it moves into the shock. The moving of the shaft into the cylinder also cause’s an air spring effect on your shock. This air spring effect is more noticeable on an Emulsion shock verses a reservoir style. This difference between Emulsion and Reservoir shocks in most street applications is not significant. For off-road use, if you have the room to mount the reservoir, we highly recommend it.