I fly all the range of the arc 630, 840, 1120, 1510.
2001 model and now all the 2002 model prewedged by factory.
I'm 65 kilos.
The 630 is little bit to fast in my opinion I would have not wedged it.... but I use with a very short bar to keep it under control, it doesn't like too much gusty wind so you have to flight it with some tension on the brake or it will luff (invert) at the edge of the window. My range 20 to 30 knots... Best 50 cm bar.
The 840 is by far the best kite in the line, with the right turning speed and with good range 14 to 23... Best 65 cm bar.
The 1120 is little bit slower then the 840 but is still OK with the internal bridle and the 2nd brake kine attachment, will fligth fast as an 840 my range is about 11 to 18 knots. Best 65 cm bar.
The 1510 is slow, even with the internal bridle and the 2nd attachmen, but have power to sell, is like a 4 weel truck as soon as there is enought wind to make it flying you are already going.
Is little bit tecnical to flight as you have to keep always some tension on the brake or it will luff (invert) at the edge of the window, must be specially carefull in Jibing but no so much in Jumping as long as you remember to turn the kite back.
Still easy to relaunch if there is enought wind.
The problem is that most of the time you are flying in very marginal condition and just a drop of 2 knots on the wind and you are swimming.
" but this is the same with the big inflatable "..
Need to use a big bar 80 cent. My range 8-14 knots.
In my opinion You have the same power with the 1510 then the stack 1120 - 840 with a lot of less hassle, better jumping and relaunching.
I love the Arc specially because I can do all by myself solo launching, landing etc. and specially because they are very hard to luff and easy to walk around and do your stuff on the beach....
Autozenit feature:when I'm on my arc I can usually help people in need in water as I can use both my hand with no need to look the kite as you always know that is park above your head. I know that for professional the inflatable have better performance but I will always keep them in my quiver for that day where you go in new place and you are alone!!! Also in the snow place!!!!
Bu we have no snow in Bali, but after all I heard about snow kiting I'm thinking to go back home in Italy next winter for holliday.
I have a 1510 to sell used 6 times at 600 US$ kite only really really like new... If you are interestd e-mail me: email@example.com