I test-flew this bag, and it performed beautifully.  It's quite big for luggage that qualifies as carry-on, and it does indeed fit into the overhead compartment.  I carried clothes for four days in the bag, plus some extra clothes I bought on my trip. On my return, I really had to stuff the bag to get everything home. I think the softness and flexibility of the plastic case helped in this regard.  It yielded nicely to overstuffing.

I cut out the straps inside the bag to make a bigger cavity, so I could pile things in. But organized people will probably like the straps just as they are.

I found the exterior clip-style closing devices easy to use, and the combination lock convenient. I also like the looks of the bag with its chic black-on-black striped pattern.