How do I stop OS X auto-correcting three dots to an ellipsis?

Thanks for the tip. I'll do that. It's highly unintuitive, though, since an ellipsis is in no way a dash, which makes this doubly bad UX. I wonder what other non-dashes that change will affect?

Is there some special reason you want the other “smart" punctuation but not elipsis?

Yes. Because a "smart quote" is still a quote and looks better on the page. An ellipsis is no longer just three dots and looks worse than a single glommed together glyph. Other than perhaps on Twitter or in some other instance of greatly restricted character count, I can think of no logical, grammatical, or other reason why a single glyph is an improvement over the intended three periods. A writer usually uses an ellipsis to designate something's missing, but the minuscule little glyph is barely recognizable, reducing its impact. It looks like a sad little electronic smudge.

It's irritating that an OS would automatically change something that I deliberately typed but give me no easy option to undo it after the fact. I have to fake Apple out to get it back, and in some places (like the Notes app, which started me on this thread) it's nearly impossible to do so.

Apple used to be about preference, now it's Apple's way or the highway in so many things. They're slowly morphing into a prettier version of Windows.