What "considerable differences"? Were there some 20, or even 10 years ago? Sure. But now - not so much.
bolds are mine
There is no "safety" difference between Spirit and ____ (insert favorite brand here), nor does any airline advertise that there is. "Crew experience"? Same thing, at least in the flight deck (and I've yet to hear of more than 1 accident investigation rule that either a contributing factor was FA negligence, or that a significant number of lives were saved due to the experience of the FA's. FA's have done their job when called upon - though I do recall one accident where the FA's didn't evacuate the aircraft b/c the flightdeck never issued the order. The passengers, like the FA's, just sat there and burned to death
). I'd bet Spirit flight crews, are, on average, more experienced flying into the non-radar and mountainous terrain environment of Central and South America than the average crew (no other US airline flies these routes as often as an overall % of their flying), and can operate their airbus just as well as any other crew in domestic US flying. Flying outside the US is considerable different than the coddled, radar environment of the US - hence, why flying in the US is so safe. Heck, almost 1/2 of all of a legacy airline's domestic flying is now contracted out to an RJ operator - if you're concerned about "crew experience", you'd likely be better off
not flying on AA, DL, CO, or US - fly a LCC, like JetBlue, Southwest, or Spirit.
As far as leg room, you have none on Spirit, and only a tad more on other carriers in steerage. Most of Spirit's depot level MX is contracted out, just like every other carrier. While Spirit's customer service philosophy is horrible, I can't say that other carriers have a significantly better one today (what they
had is not relevant - 'what have you done for me today' is the new paradigm). There is no product differentiation anymore.
A "more service-oriented airline", "superior goods"? If you're flying either domestically within the US, or between the US and Central/South America (Spirit's competition), which airline would you be referring to? JetBlue is the only '4 star' airline that Spirit competes directly with (Frontier and Midwest are the only others in the western hemisphere, but Spirit doesn't fly head to head against them). Spirit, just like every other airline they compete with (excepting B6), is a '
3 star' airline. Who exactly would be the "service oriented airline" that will steal away all of Spirit's customers with their great service (Spirit doesn't compete against the likes of Singapore Airlines and all those other true 'service oriented' airlines)?