1. I find that very hard to believe, sorry.
2. Uh? Relaunch is good, but not as fast as the SB's I've flown.
3. You're doing something wrong
I don't know what you consider fast turning, but the SB14 I flew, would rotate and be flying in the new direction much faster than the XB16. The XB looks
like it's turning fast, but that's due to the AR
Same goes for relaunch - the XB gets up on a tip and floats out to the edge of the window easy, but the SB, when downwind, would rotate in place then jump into the air...
If the kite is falling out of the sky, there's something wrong with your technique... well I assume so cos it used to happen to me but doesn't now unless I balls something up