After some more testing I can say...
The sensitivity is too high, which is also a problem in the menus (with TP I didn't have this problem).
Jumping is quite a bit harder than using TP.
Sometimes the boat seems to fly (the jump then is way to long).
The timer behaves strange when steering... a completely different time is shown for a moment.
The 'timing' seems different. I have better times with worse runs using JConfig.
But, sound and graphics are great, almost perfect.