Thank you TomW, always pleasant to read this feedback
IMO Pulsion 12m will have a LOWER end than sonic2 13m (in the sense of lower wind to stay upwind at reasonnable speed, while sonic 2 13m will always go faster as soon as you have a bit more wind) ; you should give us your weight and foil area if I can try to bet your low end; upwind angle should be approx the same as you will be able to ride slower (personal opinion). 20 m is fine and is my prefered length on the 12m ; 25 m (previously used and up to 29m and still on my 15m) would allow you to save a bit comfort in low end (the difference on lag is not so significant on the Pulsion because the rear line tension is higher than sonic2 so it can support longer lines like a LEI.
If you can drive a sonic2, Pulsion will appear really easy, no special technique (very close to HL and even more stable at the zenith) and Pulsion almost never dies at the extrem window like Sonic2 or others high aspect ratio in light wind: you can most of the time get out of this dangerous situation by send the kite upward without backstall (weight and good turn effect);
Its power during the waterstart loop will surprise you at the first trials vs sonic2 but once you know it, it leads to easier waterstart in marginal wind; working the kite in lulls is also more efficicent than sonic2.
2 drawbacks IMO:
- the comfort at higher end vs sonic2 , even 13m I think ;
- more fragile in case of front crash (if you choose 27gr or 32 gr for intercells), no Ultralight not adapted to beginners or in case of agressive soil at the launch.
-less speed at high upwind angle, less hangtime "old school type" if you like to jump (but still ... I did the best jumps of my life with a TT and my poor jump level...)
But it will ease the transitions in low wind thanks to its stability with slack lines and long time before it drops in the water. That can make you envisage to follow the swell downwind in low winds . Relaunch is also far better (if you relaunch within 2-3 minutes at least).
Now in complement of the HL 9m, you could envisage a Pulsion 15m; less fun in turns and swell, but it is my prefered kite on flat water below 7 knots, with even more power and same stability (Pulsion 18m is a bit less stable because higher ratio, hence not necessary for light weight riders)