I've recently picked up 10.5 and 14.5 Ion3's
I use to ride a 16m x-bow and 12m Boxer sle. I am 100kgs and a immediate rider. The 14.5 appears to be as quick as my old 12m. The 10.5 is a great jumping.
I have had the 14.5 out in about 20 knots, then came in and changed to the 10.5m which I rode comfortably in 27knots. Send me an email if you want ask specifics on setup etc.

Jan, I've been riding Ion's for two seasons,although due to eye injury missed most of last summer....but thats a long story...I,m a 100plus kg and i really like to make my kites work hard...especially in the jumping department...
my quiver is 8.5....my absolute favourite , 12.5 ...and 16.5
i have two boards ...one is 135x40 and the other is 152x41cm
the 8.5 works great for me from 20kns with small board....although i do like the 152 when the bay is choppy...top end for me on the 8.5 hasnt been tested but i didnt have any issues in up to 40kns ion the bay the other day....the kite is a jumping machine.....i prefer riding it in its 4 line set up....
the 12.5 kicks in for me at 15kns although i need higher gusts to get my kicks...its top end for me is around 30kns...but i prefer to switch to 8.5 if wind staying that high for lengthy period......kite works great with 135 board but for some strange reason i prefer the 152 even in high wind....i love the feeling of pushing the edge of the big board into the water...great leg workout.
the 16.5 is my cruise kite....it starts at 15 for me but u can cruise around all day when wind is staying around that level.....ive had it out when wind gets up a bit...mid 20s but its not a comfortable ride so again i switch down if wind stays constant in 20s....
im a huge fan of the ion...i especially like its ability to take punishment.....
hope this helps
col