I've got a '96 S240 with a much less powerful AQ31 / DP. With a freshly cleaned bottom I can get 28.5 knots flat out. The S23 is a little bigger but the KAD 32 is about 50 HP more powerful so it should go well.
I have an S23 with KAD 32. Have been very pleased with it and seems a good seabot for it's size. The top speed we have attained is 27.5 knots with full fuel and water tanks and plenty of cruising gear - could in my opinion do with a little more power.