The product IMHO is bland, and boring. However it does what it's designed to do - transport lots of people safely from real airports at a fair price whilst generating return to shareholders. Investment in it would be good, but those with wow factor and bling aren't on the same strong financial footing (Norwegian, I'm looking at you). Others provide an identical product to U2 but aren't likely to be with us for much longer.
However, they are growing steadily and delivering excellent results in a challenging environment. They'll survive the next 9/11, recession, depression or whatever black swan event comes their way. Not only survive, but they'll make money too.