Agreed. I sometimes have two personal items as well (either a backpack and camera bag or maybe my backpack and my work laptop case). Regardless of whether both could go under the seat, the smaller one is going under the seat.

Additionally, I have no problem putting my personal item in the OH bin when it's my only carryon because my personal item takes up less volume/space than the roll-a-board I could otherwise bring on and put up in the bin. It's rather amusing to me that the opinion of some on here is that although I choose to check my space consuming roll-a-board and instead put a bag up there that takes up LESS space than said roll-a-board, thus leaving a little more room in the bin for others that I could otherwise take up (and will have to wait at bag claim for it after the flight), that I'm somehow the "selfish" one to those who do bring their roll-a-board as their carryon.