The glue-in bolt is quickly becoming a standard in the rock climbing community, but in my experience it seems that cavers have yet to learn that they exist. I think it's a no brainier that cavers should be using them; they don't require hangers, they are better protected from corrosion, they are virtually indestructible, and installing them under a ceiling is totally legit. The only drawback I can imagine is that they are essentially permanent and cannot be removed without a variety of power tools, but on the other hand they would eliminate the existence of bolt farms at popular pits.
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