Good point about the "expansion" feature. When I unzip the daypack, my handbag goes inside, so I am still legal w/1 bag, one personal. Heck--my day pack is still smaller than most bizmen drag on--plus their coats and laptops and...
I love keeping that pack on the floor by my feet, too.
I found the CR900's bins fit my roller!! but I do like the pink tag at the gate for convenience--thta's why the zip off pack makes so much sense for me--I don't risk my netbook or otehr junk I might NEED liek a book, glasses, etc...