A major contributing factor can be tire pressure. Have you had you coach 4 cornered weighed to establish proper tire pressures? After weighing our coach we found that the michelin recommended pressures were over 20lbs less than we were set at. It made a very noticeable impact on the ride.
The dealer sets pressures to the max, not knowing how you will load the coach. For us that was 120 lbs. After weighing we are set for 95 front and 100 rear.
Of course there is also the possibility the new shocks are not proper. Our son had new shocks installed and the dealer seriously under sized them. They installed shocks for a much lighter vehicle.