17M Speed @ about 75kgs
On my Slingshot Glide (ultra light wind board) I can get up & going @ 6kts then upwind with any added apparent wind. But (esp if its not a super consistent 6kts+) its a battle to maintain anything workable unless you just keep going in a straight line. At anything consistent above 7kts then ur away - no problem.
On a 137TT the fun starts at about 8kts thru to about 13kts when it begins to feel like ur wakeboarding behind the Manly ferry. You could still work it beyond that, Im sure, but by then I reckon its time for something smaller & faster.
I reckon its a great option for lightwind AND especially good for heavyweight kiters in lighter winds because it really does have the grunt of bulldozer. When you push and hold a really solid edge this kite points upwind like you wouldnt believe. Unreal.
(sorry - dont know anything about the psycho's

)