And after you have all went to all that trouble of welding/fuzing two pieces of plastic together, you all find out that the biggest problem is the Loop itself, especially if there is no sink-tip being utilised and a 'Blood Knot' is the main knot prefered instead of the loop-to-loop-method.
Of course most sensible fly flshers use the loop-to-loop-method or one thats equally as good, but there is always the odd 'Numpty' who would prefer to do it his way, and that usually ends up in a disaster!
Myself I prefer the home made Braided Mono Loops because I can make them any length I want and I cant whip them if I want before slipping the Aquasure onto them, unlike the made-up one's that are over-glued below the loop meaning I cant thread my fly line through & up to the loop. I've been making my own loops for over 20 years without any problems of breakages or anything, but I've had problems with these bloody-so-called-welded-loops though, Orvis especially.