I would say to the contrary - there is a vast difference between Spirit/Frontier and Delta, and big difference between Southwest and United. However, only Delta is able to establish a reputation for a premium product that does get a price premium, and Southwest continues to maintain its own reputation for no-frills value with great service, often at a higher price than Spirit/Allegiant or Frontier. At this point, only United and American are struggling with their own identity, lacking a clear product vision, any communication of their value propositions or what makes their products desirable - and what do they have in common? They are both led by someone who is a protege of arguably the worst (from a customer/employee perspective) airline leader in history, next to Frank Lorenzo, Ben Baldanza.

Delta has made it clear that product quality matters....features matter....service matters...and people WILL pay a reasonable premium for a better experience.

Airlines are doing well today because the economy is strong and fuel prices are under control - that can, and will change in the future - and when it does, airlines who don't have a plan to capture and maintain business from a shrinking customer base will discover they are in a very bad situation. I support foreign ownership of a US operating airline, provided the foreign owner is from a country that does not have economic or political conflict with the USA and crews are US citizens or residents, as it would inject capital into the industry and create competition for US carriers, forcing them to either innovate or be swept away.