I never had a problem with the upwind/downwind scenario you cite, when i'm flying my Picocub at 20mph in a prevailing 5mph I realise there is no such thing as an upwind/downwind situation but when i'm flying my Radian at 10mph in a 5mph prevailing it does occur, I realise that turning downwind will induce a stall situation, the tighter I turn the worse it will be and I have to fly accordingly..
to quote Dave Thornburg, from the "Old Buzzards Soaring Book" which I am led to believe is the bible according to Glider pilots all over the world..
"Any time you turn downwind, your model has to accelerate (relative to the earth) in order to catch up with the river of air and regain a comfortable airspeed. This acceleration costs you some altitude, and while it's happening the rudder is going to be sluggish, since it is to short of airspeed."
This to me as i glider pilot is realworld..it happens, but you are telling me it doesn't..I don't fly a Vapor inside a large aircraft somewhere over the states.. I fly a Glider down at my local playing fields..
Sorry if my post appears "newbie and borderline moronic" ..