I had a 2015 P2 with the 200 Pro XS. My 2019 Classic has the Merc V8 200 4S. Gas mileage is pretty well the same as verified on my Vessel View. I do like the quietness and torque of the new 200. Also nice to have more room in the rigging area due to the loss of the oil tank. If resale down the road is a concern for you, a 4S will be an easier sale, as already there are a lot of boats with the older Optis sitting because many now want a 4S.