Yep but any other equipment difference may be enough (or maybe not). If you went from a CRJ to a Dash and called in saying you were afraid of turbo-props you might get a switch too. I don't have an answer to every hardware combination, just saying that it seemed like US made a good effort to re-accomodate me when it was the hardware, and not the schedule, that changed, when I gave them a reasonable justification.