The distance doesn't help much BUT... Lets talk about Reverse Osmosis (RO)...
Basically, In RO systems the water slowly seeps through the membrane. This membrane if I recall correctly is actually the outer lining of a pigs bladder. Does that water taste different now?
Any way this membrane is so fine that that most of the contaminants in water are held back by this membrane. This membrane is washed clear by an almost continuable dribble of water to the drain so the membrane does not become clogged. The water that seeps through the membrane does so very slowly where it is then held in a small storage tank. When you pour off a large volume of water this storage tank is depleted and the pressure drops off until the storage can be replenished. Check the capacity for your unit and it may also help to spread the demand out over time. The piping is a long run and there is friction loss associated with it but I suspect your problem is much more the demand that you are placing on that old pig bladder!