I had the opportunity to test the Chrono 15m for 7 or 8 times. Since I am always reading up here. let me share my experience with you.
I had the FS Speed 4 15m to compare and also my own Dyno 18, 2011. Tested on flat water with winds from 10/12 to about 20 with gust up to about 23 kn. I am 78 kg, ride oldschool. I rode the Dyno for last 2 years (up to 22 kn), FS Speed3 15m the year before that. And before that lots of tubes and foils. Biggest twintip 128. I am used to sailing with a lot of pressure from the kite. I write this experience exclusively from the Oldschool point of view. Not light wind, race or freeride.
Chrono has less static pressure than Speed4 and Dyno. Goes far to the edge of windwindow. At first you think, where is the wind gone. Light barpressure, but also light on the trapeze. But right from start with light winds under 20, jumping was a big surprise. Lift and hangtime is in different category. I did not use the depowerstrap on the Chrono. So I don't know it's high end. The light barpressure was never a problem for me. In jumps with multiple rotations and board-off, one hand on bar, the kite was always there were I expected.
Chrono feels lighter, faster and more playfull than Speed4. Chrono accelerate faster. Gets you going quicker. Kiting in small lagoons is no problem. I did have trouble getting out of transitions with speed. Kite turns faster than S4 but slower than Dyno.
I was concerned, hearing the stories of the kite being instable. But I find that not the case. It can lose shape after jumps that go wrong with no pressure on the lines. Pulling on the front lines made it come back to shape. I found it hard to reach for the break line quickly, so I pulled the front lines as quick as possible. It worked so far. I do find it very difficult to launch the kite of the beach in 20+ kn.
FS Speed4 is stable and easier to get in the air. It gives you more power, not as much as Dyno, but lift and airtime was a lot less. Dyno has less hangtime. Dyno, with 18m2 and higher windspeeds, gives more pressure, physically more demanding, shorter turn cycle. In low wind I could squeeze out a Jezuswalk, not with the Chrono. Which has a bigger turn cycle with even pull true the cycle. The Dyno with smaller loop gives the pop to get board back on your feet. Chrono is pretty fast though, I guess with better technique would be all right.
Chrono's upwind capability is of course super too.
The Chrono for me is an magical kite for the lift, hangtime and easy handling (feels reliably with tricks). I never thought the kite would be so much better in lift and hang, than all other kites I have tried. I have never been so high on a big kite. In conditions, I would normally be content with a floaty 720 board-off (or maybe 1080) this kite made me think of what to do with my board during 1080 b-off. Also because of it's reliable nature. Always there where you want it. Not having a micro loop and stopper can be solved by using a north bar.
Some people seems to have problems (collapsing) sailing the kite also in steady winds. Maybe experience or feel for foils is a necessity.
And now I finally have the airstyl 18m for testing. (: