I did not know you were that much into wing bragnouff.
Then it makes sense (at least for now) not to have a 4 m2.
I havent used the 3 and 4 m2 Peaks much, since wingfoiling, but I start to use the 4 a bit more now, when experienced and discovering low wind wingfoil is possible but not fun compare.
Size difference for me (experienced wingfoiler) is I need 1 to 1½ m2 more wing than Peak kite size, for sweetspot.
When I can ride a 6 m2 Peak, I can not wingfoil
When I ride a 5 m2 Peak, I can almost wingfoil with a 6 m2 wing - but a bit too little and only doable in gusts, and not really fun.
When I ride a 4 m2 Peak, it is great for something around a 5 m2 wing and the fun starts from here.
When I ride a 3 m2 Peak, it is spot on for "not too big clumsy wings" wingfoil.
I deliberately wrote "when I CAN ride a 6 m2", as I do everything in my power, to avoid the 8 and take the 6 as so much more fun and pretty close in lowend.
But sometimes I try too much to avoid the 8, and take the 6, where I would have been better off with the 8 m2
If you wing a lot, then it makes sense with 5 and 8 only - 5 is still somewhat more "nifty" than the 6.
Peter