I have one of
these. I did all all day course last fall and never took it out of single point. I was comfortable all day long. The one thing I would do differently is not get an HK hook for the rear hook. It is not exactly easy to go from single to two point as the spring is very tight. I imagine more practice and use would make it easier.
http://www.tacstrap.com/ . I have it and love it . Works well with the IKH Slap plate they also sell . Inexpensive for both .