Re: loop to loop connection
My new Orvis line came with a welded loop at the terminal end, so I attached my twisted leader with it's loop to the fly line loop. Neither married very well. In addition, the loop in the end of the fly line was quite large and I had trouble with the connection in my guides as it hung up constantly. Now I've noticed that the loop has cracked and now causes a hinged effect which impedes a good casting loop. I feel like I've given this my best effort and will now cut off the welded loop, attach an 18-inch piece of 20lb fluorescent mono via a Nail Knot to the fly line, with a Perfection Loop in the end to which I will affix my twisted leader for a loop-to-loop connection that I have used for years before trying the welded loop. Long answer to a seemingly simple question.
As far as using the mono nail-knotted to the fly line with a Perfection Loop in the end, this is a perfect system for changing leaders during the year, and, believe-it-or-not, the loop-to-loop does not seem to get as hung up in the guides as the fly line welded loop did.
I fish, therefore I am - but I gotta go to work first..."piscari ergo sum"