In the just over 1½ years I have had Peak4 (and 5) kites, I have checked my log and used 5 and 6 m2 the most, in particular when you know they are the most overlapping, they are by far the most used sizes for me:
Of course it is influenced by the fact that when more wind I also wingfoil, and when lots of wind I often waveboard kite also or instead.
And I have not had the 6 m2 for more than a year, so this size IS the most used in fact.
The 11 m2 I had very shortly and sold it again, the 8 m2 does it for me as the biggest size @78 kg, and then other kites when less than 8 knots of wind.
I tend to avoid using the 8 m2 if in any way possible to ride 6, but when wind below 9-10 knots the 8 is my "go to" kite, unless too small.
The 4 m2 is the most fun size, but often I am out on other gear also or instead when this size apply.
I might have missed some logs, it can happen I forget, but it gives a rough picture of which sizes I use how often here in Denmark.
Could be interesting to hear how often others use their sizes?
Peter