Ive always used a loop to loop connection and probably wont ever change---The loop in the flyline is whipped and coated and the loop in the backing is a big bimini, big enough for the reel to pass through so i can change lines or mix and match reels. It goes through the guides both ways without a problem.

FWIW---Before i knew the knot was a castwell knot, somehow i lost a leader while casting for little brookies on the n. branch of the au sable---probably by sloppy casting. Now i just use a loop to loop there also.