Good topic Bracuru, from a thread 20 minutes ago
Regarding mast/strut lengths, my experiences, having an 83 cm, 90 cm , 100 cm right now:
83 (or even 70 I think) is great for the very marginal winds, particularly in dead onshore marginal it provides an option to ride when too little wind to keep a light kite in the air without actively flying it, so not possible to drag out between sand banks to deeper water.
90 is a good compromise for everything, cheaper than a long one, and okay for most things.
But I still ventilate when frequent chop waves, which are the most normal conditions.
100 is the only one I like in normal "wind" waves - even the 90 is often too short here, where you cross and carve in close steep waves
And for riding really powered upwind, it is also better of course.
For jumping (strapped) and rotations, the shorter the better as you can tweak and turn and twist the foil way easier the shorter the strut
Strapped you can also ride faster and ventilate slightly, and recover most often, contrary to strapless, with a much shorter strut.
For waveriding in "perfect" smooth conditions, glassy and long swell period, a short strut would most likely work fine, and be quite lively.
In anything but that, which is our most frequent conditions, the longer the better IMO.
So yes, I also prefer 100 cm over 90 cm just like you Bracuru - but we have to look into ourselves, and say it might just be "getting used to the medium ones", or it could be the longer ones are simply better overall - difficult to say for sure