I have 83kg's, I have a strapped naish surf 6'1.
The 12m gets me going around 13knots, because it is fast, and I can work it well and due to the volume in the directional.
I find the 12 pretty powerfull, with a long depower rope..it works well..
My son and his friends who fly C4 and are much more dare devils than their father ( me 55j) all say the Catalyst jumps pretty easy and is going high, but alls tell me the same it does not have the hangtime of the C4.
To me not important, as I am mostly killing and carving the small waves we have; and for that the kite is so nice.
Again I wantto mention the easy starting from the water after I dropped it...I had the sporrt's last year, this kite is much more fun for me, especially when I dropped it, it starts so easy.
All I can say is, that whoever is looking for an easy to handle very good alround freeride/wave kite, this is the kite, it is also very light!
For the guys who are more into freestyle the C4 is the kite, more direct power, a bit faster, and longer hangtime!