User Review: Black Diamond Big Gun
I've been climbing in the Big Gun harness for a little over a year now. I used to hang in it for about 8 hours a day, most weekdays, at my old job. It did incredibly well for distributing weight so my back wasn't killing me.
My ONE complaint (and it is actually a big complaint) is that it needs TWO waist buckles so that the gear loops and bullhorn waist belt are centered. As it is, everything is offset, and you have to shift your harness whenever you stop hanging and start climbing again.
Other than that, I love this harness. I use it for trad climbing, and usually for sport climbing too cause I can belay for hours and never get tired.