So has anyone actually been charged or is this bullshit?
I have DK bag I haven't used in probably 5 years.  I do remember when I did used to use it more often, I would get hassled HARD for it being oversized, even then.  I was always able to talk my way around the fees, but one time flying United at LAX and arguing with the manager for half hour, I literally had to pretend to leave, and then came back in, spoke to a different counter agent who didn't hassle, and made my flight.  
I'm flying to Phoenix on Monday with Southwest Airlines, and now a little nervous due to the size restriction.  What you guys think?  Time to hunt down a smaller bag?   Anybody know if that Odyssey Hawk's Nest bag is within the oversized dimensions?