About a year ago I flew with American Airlines from Vegas to Miami and it was a 1 or possibly 2 star experience at best. I'm not sure what's changed - I know they've had a turnover in leadership at this airline and have merged with US Airways, but I can truly say that this flight was much improved and has earned them 3 stars. The process of getting boarding passes was quick and simple at the dozens of kiosks they have near the check in counter, the flight boarded on time, took off on time and arrived back in Miami about 20 minutes ahead of schedule.
The only critical comment I'd make is that this flight was about 4 1/2 hours long and it'd have been nice to have an entertainment system at every seat, but they did have movies and TV programming running on the overhead screens the entire time, rather than a seemingly endless loop of advertisements for AA as had sometimes been the case in the past.