There is a Leatherman Bit kit and it covers the bulk of the work I've run into except security heads. Even so, you can still use their standard bit kit on the New Wave (which I have) if you wish for the full size. As mentioned elsewhere, I'd rather not put the amount of strain on my hinges if I can avoid it, but for lots of Q&D jobs, the LM shines. I keep one of the thin bit packs in the same case with my LM, so I'm covered about 98% of the time.
True, I'm locked into LM bits this way, but I generally bring real tools to the job site if I'm going to be needing something substantial. I also try to carry at least basic tool sets in vehicles, so I have a tough time imagining when this would be an issue. In a real emergency, if I'm whipping out the LM to work with screws, I'm not going to care about the hinges much and they've already proven themselves after some pretty intense torquing, so my concerns are more about keeping my LM New Wave functional for a long time than for a one-time critical job.
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Experience is a hard teacher because she gives the test first, the lesson afterwards.