Oh God yes! You get an obscure syntax error and it really isn't obvious what the problem is. It would be useful if syntax highlighting marked smart quotes (outside of strings) with a bright red background or something.

I work with high-profile editorial and art staff. They need those quotes! They're often great at knowing how to insert them themselves, but others need that short cut. As it is, the quotes are hidden at `Opt + [` and `Opt + Shift + [` on my machine (Canadian English layout). [Oh, the war stories I have trying to sanitize text for moving from platform to platform...]

We're not the only ones using keyboards anymore, and we're in the minority of those who do!