IEMs are a different issue than ALDs; not sure if they're relevant to this thread.
As for ALDs, I've never used one, and haven't liked the recordings I've heard with them. And I agree that using a house ALD is unethical, unless you're genuinely hard of hearing. It's akin to parking in a handicapped space when you're not, in fact, handicapped. Don't be That Guy. If you want to go the ALD route, buy your own.