I have the U420XW.
Only once have I not been able to fit it in the overhead bin on a large aircraft. I think this was because it was stuffed full, extended, and then I had something in the outer pocket. So it was girth more than the standard dimensions of the bag that kept it from fitting.

Of course, on smaller planes, this bag always gets gate checked.
The width is not a big problem, though it does not fit well down the aisle, and certainly can't roll it down the aisle.