RE: release for off string vs. loop
I shoot off the string as well with a Cobra Black Mamba - I like the design, which was made for that purpose, and the trigger feel.
I used to shoot a Winn release, and it did great off the string, the only knock on it was that it is a "glove" style release and I couldn't get it out of the way when I needed to use my hand.
Either will work very well off the string.