Sluggo, I agree with 99.9999% of your post, except for the above.

I really do think those sizers are way too small to accurately represent the true capacity of a bin. My rollaboard is very easily placed into an overhead locker without a lot of pushing and shoving. However, it does NOT easily fit into the sizer due to the way the wheels are placed and the hard sides. It actually takes a significantly greater amount of effort for me to maneuver my bag into/out of that sizer than it does to lift it up and place it in the overhead.

Especially during the height of sizer enforcement, I wish AA would come up with a more realistic device/mechanism of enforcing the carry-on size.