Thanks a lot to all of you for your inputs.
So, to sum it up my thoughts are so:
My formula/8.5 adds something like 50% to my TOW compared to the freeride gear and it works, great.
A bigger rig will add even more but:
For recretional use will I get the same TOW/fun with t.ex. a twin cam 10m2 early planing freerace sail compared to a 11m2 race rig?
Will I get a bit more planing (TOW) with the twin cam than the race sail at the cost of pointing and competitiveness??
The 10m2 freerace sail is less high-tech, need a little shorter boom and mast=better handling and less$$$..
Won't the freerace sail last longer than the pure racers? (a friend of mine got a NP 2007 race sail for his formula this spring, after four sessions it broke two cambers... it's a $$$$$ sail
. Last year a lot of NP X9 $$$$ masts broke. Some of them on the beach when exposed to sunlight).
Anyway I will try and borrow a race rig one of these days, it may answer a lot of my questions