As an attorney, a $5 million fee sounds pretty good.
However, the second poster is probably right in that the CoC is strongly worded in US' favor. However, if one could show, for instance, that the company was unjustifiably blaming "weather" for factors within its control, then you might have something. Nonetheless, it seems to me that the best and most effective approach to poor service is to stop giving them your business.
Even if they blamed weather, the CoC uses language like "best effort" to get you to your destination and pretty clearly establishes your right to diddly squat if you get there within 24 hours of original schedule. I'd think the only damages you could get would be the value of denied hotel/meal vouchers plus a punitive award that would almost undoubtedly be reduced into oblivion on appeal.
I guess one could say that Tempe knows the cost AND the value of good legal representation!