I'm on CLT to MEM now, the FA wouldn't let me bring my International size spinner on a CRJ 900, even though it would fit fine. She said no carry ons were allowed in the cabin for weight and balance reasons.

I passed at least 5 wheeled carry on bags in the overhead bins on the way to my seats, so either deadheads / non-revs don't follow their own rules, or they are only applying rules selectively.