mybagfits ... I believe you have accurately outlined the problem. There is absolutely NO gate enforcement at FLL for USAir. I fly enough to know what size bag fits in the overhead compartment. I put my laptop bag under the seat. IF I had known ahead of time that space would be an issue, I would gladly pay to put my properly tagged (and necessities removed) bag in as checked luggage. I saw overheads that were "full" because the bags didn't (or weren't made to) fit properly. There was actually quite a lot of room available IF everyone had placed their bags in properly and put their smaller items under the seat.
We were just very disappointed that the GA didn't enforce the "rules" that those of us who fly more often abide by. If the rules are never enforced, how will those who travel less frequently know what is expected? When we did a TATL last year on Virgin, they were VERY specific about what size carry-on was accepted and said in no uncertain terms they would not allow anything larger. Everyone was subject to the same rules and the GAs made sure it happened.
I won't keep this thread alive much longer as I really didn't intend for it to become a rant. I know those persons who belong to FlyerTalk know and abide by the "rules of travel". It is a shame that air travel has stooped so low and become so unpleasant.