One thing I recently observed while flying from Charlotte, NC to Phoenix, AZ and back two weeks later, is the incredible amount of carry-on luggage people are cramming into the in-cabin overhead storage on airplanes these days. I suppose it has a lot to do with checked luggage charges, but come on, people are bringing wheeled carry-ons that rival what I'd need for a week's hike in the mountains!
What this causes is totally full overheads that hardly close. Airline attendants spend a lot of time juggling overhead bags around to make it all fit, plus when leaving the plane, people are passing crap up and down the aisle to get to the owner. A real pain in the rear in my judgement.
My preference is to carry nothing on that won't fit under the seat in front of me. That way, I don't have to worry about not finding enough space in the overhead to place my carry-on. But, I seem to be in the minority these days.
I am SOOOOO glad I don't have to fly that often. It is definitely not as enjoyable an experience as it once was. I remember the times when I flew to Germany and back on a 747 and had an entire center seat section to myself so I could stretch out and sleep. Wonderful days that are no more.