The photo below shows my new ATC Nano. Sweet! This is an innovative new belay device that is definitely going to be in my ultralight mountaineering setup from now on. After all, when you're bagging multiple 7000-meter peaks in a day, you don't want to be held back by a bunch of heavy technical gear that's really optimized for roadside cragging.
Unfortunately Black Diamond's documentation does not provide a lot of detailed information about how to use the thing properly. It came with one of those poster sheets with little diagrams without words, but every diagram has a skull and crossbones. Has anyone had a chance to rappel or give a lead belay with one of these so that they can share their practical experiences? I'm especially interested in any info on compatibility with various types of ropes and harnesses.