I regularly ride both a 2018 SA and a 2021 SL. Have also been on the newer SA, like with Larry and others. Both wakes are amazing. I feel the SL when weighted is a bit more of a longer ramp whereas the SA is more vert. Both have nice transitions and clean up easy. Now, as with any boat, you can't run full ballast and slow, but half ballast or so and 21.5 is still great! Running over 80%, you'll need to be around 22. The 400 with the new 1.7 gear drive ratio is more than plenty at your elevation. For surfing, most keep 500 pounds of lead on board to help on light crew days. Both the SL and SA we ride are set up about the same. Both great boats. Get the 1 that calls to you and fits your needs best. Both these boats are at my dock, we wakeboard and surf both interchangeably with no real significant performance difference other than what I described earlier. Enjoy and thanks for the wakeboard question!!