Hi W100. I have had the RS Formula since February. My previous board was an F2 FX IV (2007).
I'm not a top racer, but I find the board planes very early for me at 90kg. Some others who have tried the board say the angle upwind is not quite as high as 167W or JP Power but RS Formula board speed is better so that compensates. I have found board speed to be better than many others at my local club, but my weight may contribute to that compared to smaller sailors.
The board seems to like a smaller fin than my older F2. VMG M75 works well for 12.0 but K76 was too large and railed the board up too much downwind. When powered up with 9.0 or 10.0 a 70cm is fine.
Mast base position about an inch behind centre seems to be the agreed sweet spot for the board, regardless of sail size.
Remi (local Exocet dealer at The Windsurfing Shed) who has used the old Warp 100 says he thinks the RS Formula is easier to ride. I never tried the old one but this board is easy for me to handle, even in 20 knots and above.
Remi scored results in the top 5 for several races this past season, which was an improvement for him.
Oh, and the board is silver with nice RED stripes - not pink

Hope this helps.