I've tried it. Compared to my Duotone Warp Foils it is slightly heavier, but on the water I didn't find that noticeable. Powerful and stable profile, despite the 3 cams. Well built, seems very solid. I found it a very nice sail overall.
I think 4 cam are more tradition and a way to differ the race sails from the free race
on a 4 cam sail there next to no tension on the top camber so I don't think it matters, just my 2 cents. The sails are good. I am just back from waterz long distance in Hvide Sande. 1. Race point seven F1 sl placed 1. 2. And 3. I was making 2. Place. Don't think the weight matters very much.
Does the 5,8 work with a 91 cm Foilboard? I have a 7,0 Foilsail that is too big sometimes. Would use it with a 740 sabfoi Slalomwing. I already have Point 7 masts from my windsurfing sails.