Hayashi,
Your forgetting a few things... Another quad, or worse yet a truck which is moving can create many times more force than the 2500 lbs the winch can theoretically handle...F=M*A...
Call Warn, they'll tell you not to use their winch's as tow points ever. They are simply not designed to work that way...
I have to admit, I've done it to my mine a little tug once in a while, but If I was full on stuck with some one else's 600-800 lb quad (plus rider and accessories) yanking me out, let alone a truck, I wouldn't even consider hooking the strap to my winch hook. WAY too much potential force could be generated there...
Mike