you can attach lines between 5th line attachment and tips, if you adjust the tension, the kite will be stiffer, so ...
-more power
-more depower
-more reactivity
-better unhooked
-better upwind
-more instant power in jumps
-no tangles posible,
-no need too much pressure in the bladder
-don't really disturb pack/unpack
It's particularly good for new 4 lines C-kite for people who don't like fith line but like to keep the canopy of the kite in high wind.
For manufacturer, it allow you to put a thinner leading edge, for more performances. It works well for not too flat SLE too.
[source: kiteforum.com]
