Hi Deja Vu,
I've seen some discussions on other forums as well about these 2 types of sails and I'm bringing this subject up, exactly because there is a such a big price difference between these sails. I would have never believed that there could be such a big performance difference between these sails, if I would not have tried the 2 sails on the same day in the same conditions. I'm glad that the NP marketing is actually delivering what they promise.
I only recently got interested in slalom/race windsurfing. Before I was much more into wave, bump & jump on the open sea but I found that I don't have the condition any more to do this, at least not in a decent way. It must be the age, only 44 though
That's why I decided in the beginning of this year to buy a isonic 101 and have some slalom fun with it, focusing on speed, mainly on the lakes next to the sea. When I asked the SB team about which sail to use on it, they all convinced me to go for minimum 2-cam sails or full 4-cam racing sails. That's when my investigation started about slalom/race sails. I was lucky to find a NP RS:Racing 2nd hand and did not pay too much money for it. After all, I didn't know if I was really going to like it. The guy from which I bought the sail (a dutch competition sailor), told me I was about to buy the "rolls royce" of the sails. I think he was right.
I also think now that these kind of sails are more important in the moderate to higher wind forces where you really need the control. It will get a bit less important with lighter winds and huger sails (chop & gusts are less).
Jeezes, I'm gonna stop now, because i feel like I'm writing a novel.
Cheers and hang loose !