I would argue that being a lab staff is better, because you know what you're getting into. You were probably paid better, too. "cushy" is not a good thing to "prepare you for grad school", especially not for students who are noncommital (not saying that you are, but a lot of IRTAs are). OTOH, I knew a postbac whose job was to counsel macaques that had pieces of their brains gouged out (and therefore wound up with severe behavioral problems). So her job was pretty stressful.

Upshot: You made the right "choice".