The view am getting is for the main.

MK1 Landy mainsail is highly efficient sail over most wind conditions which has to well control to get the best out of it.

GP
Have more up top so are easier/simpler to use in low wind.
Plus are more easier to dump wind in high wind.
Downside more sheet load, and most likely less efficient in mid strength winds.

Kite
GP prefer to be sail higher.