Direct comparison SL 350 and SL 400

Hello, does someone have concrete experience in the direct comparison of the 350 and 400, especially in terms of pull-through capacity, switching down during acceleration etc? Theoretically, the 400 should allow a noticeably superior driving. Unfortunately, I was not able to drive a 400 and must speculate. Specifically, I am concerned with the purchase decision, to order another sales 350 or the new 400. I am grateful for experiences and advice. cardio8000