My comment re. ATRs vs. ATPs was tongue in cheek - if you check my profile you'll see why.
However, I stand by my comment; ATRs might mean a higher capital investment (and we all know that most airlines are under-capitalised), but they get their money back over time with lower running costs (and less downtime) compared to the ATP. In other words, you get what you pay for.
Cheers
P.S.: share price index? I didn't know that Atlantic Airlines was publicly listed...