I ride the 5.0
I chose this one because Im 83kg and its 75ltrs and I wanted to go approx -10ltrs from my weight. Really glad I didn't go for the 4'8" model because I'm pretty sure water starting the 4'8" model (55 ltrs would be -30ltrs for me) would be too difficult.
It's really nice to start, and carving feels good to me because its narrow - I'm used to a much wider board so it feels like a much smaller/narrower board to me.
It feels very smooth in touchdowns and the double concaves give it very good directional stability when taking off.
My only negative about the board is it's weight. It should be a kilo lighter, but it feels solid, so maybe the extra weight means it's stronger than lighter boards. It certainly feels solidly made. I don't really notice the weight when using it - only when carrying it.
It has handles on the top AND bottom of the board which is really useful.
I've been riding the 5'4".... I have one from the first production run, and it is kinda heavy, however the next shipment of boards were about 2.5lbs lighter, and the sales manager anticipated that the weight would come down further on subsequent production runs.
I've got the Sky WIng 5'0. I'm 85kg, with similar as Dommo49 comments. Came from a 6'6 x 28" 116 lt BP Sup foiil board. Absolutely love it! It was very tricky to even get on it for a knee start first few sessions, got it dialed now. The lack of swing weight has taken my riding to next level, now i stay on foil with all my jibes, go onto toeside, then either change direction with a heelside jibe, or go to switch stance riding. Really opens up the carving and playing on waves/swell having such a short board. Cranked one carve upwind and continued to almost foil out of a tack, which I've never even tried yet! It is a bit heavy for it's size, but it is solid and well constructed. At speed if you touchdown it will pop right off and re-foil. It is actually easier to get flying than my old sup foil board, even in very light conditions.
Thanks for the review. Good info. A guy I met winging at the local spot has the same board. He's about 70 kgs, and gets up foiling really fast and uses straps. Gonna ask if I can give his board a go. For my weight, the board will be -5 liters. I'd imagine it's going to be deep water starts. Good thing I started doing more knee starts on my SUP....