I carry a cheap folding knife with me while climbing, particularly if I know there is a chance of stuck ropes, grubby anchors, or we are in the backcountry. The knife is held shut with a loop of cord, but I've been hoping to find a safer, cleaner solution.
I know Trango makes a couple knives (one attached to a nut tool), and so does Petzl. What are the advantages and disadvantages of each? Does anyone have personal experience with a particular model? Ideally the knife should be wearable on my harness.
Edit: I'm really looking for a broader answer that references advantages and disadvantages, though the information about the specific knives so far is awesome.