There seem to be a only a relatively small number of variations between kite boards, barring bizarre shapes etc.
These are
1. length
2. width
3. shape - ie width at tip vs middle
4. rocker
5. rail
6. shape of base - concave/convex etc
7. flex
8. number and position of fins
9. size of fins
I'm talking twin tips rather than mutants or surfboards.
So how do each of these impact on performance?
As I understand it
Length - likely to increase speed, but decrease maneouverabiility.
Width - for a given length, an increase in width will increase the bottom end performance. In my experience, a wider board is sometimes harder to hold an edge on.
Shape - width at the tips might decrease potential for nose diving?
Rocker - I know what it is, but have no idea of the effects of changing it. And is a relatively flatter mid section with more curve towards the tips an advantage?
Rail - a thin rail holds an edge better, but is maybe a little less smooth on the transitions? Not sure about this one
Shape of base - a concave base gets planing earlier. A convex base is a waste of time. Sunny shapes like bi-concave may have a bit of an advantage in the waves, combining early planing with improved maneouverability.
Flex - more flex = more pop. Probably would increase the wind-range of your board at the top end. I reckon it might be more forgiving in the chop but not sure about that one. A stiffer board will give better bottom end performance, but hurt your knees more.
Number, position and size of fins - I've decided I like the feel of boards more if they have bigger fins on. I feel like I have a lot more control, can hold the edge a lot better and get a bigger pop. So what are the advantages of smaller fins?
I'm pretty sure that at least some of the above would normally be found obn the floor of a stable, but just not sure which parts

. Any feedback would be appreciated.
Cheers