Thanks for the reply.
I am experiencing no hinging with the loop connections, I should have been more clear. Factory loops from Rio and Airflo are excellent and I have been making my own non-hinging loops since way back in my years living in steelhead country where loop-connection sinktips are the rule for winter steelheading.
The "hinging" I am talking about the line hinging that occurs when you shoot let's say 15 feet of running line into the final backcast then make the forward cast expecting that thin line to turn the big head over.
To see what I mean, try shooting about 20 feet of the running line into the backcast and come forward. That's a line hinge. With a 10wt head the ability of the running line is much better than with a 12wt head (same running line, much heavier head).
This ability to shoot line into that final backcast provides tremendous boost to the power in the cast and it's well worth accomodating hence the spacer. It's also a tendency distance casters inherit from their single handed casting, and is not only effective but it feels good to be able to extend the length of line in the air.
Hope that made things clearer.