If you get enjoyment from playing slots, then by all means, play whichever slots you want. It really is just a matter of timing, since you will lose your money eventually if you continue to play. Personally, I would prefer that people just give their money to charity and stare at some spinning lights and pictures instead. But to each their own.

My comment assumed that someone actually wanted to minimize their losses / maximize the amount of play time given a set gambling budget. In other words, I was thinking rationally and not like the typical slot player.

I could be wrong, but as far as I know, there are no published slot payback percentages for just the slots at the airport (although you should be able to find consolidated payback info for the parent company). That being said, you definitely do not earn comps, which range from 20% to 30% of your expected loss at most properties in Vegas, and common sense will tell you that the payback on these slots should be lower than a Vegas casino (captive audience, etc). The one data point that is easy to verify is the payback percentages on VP machines (per Nevada law, a VP machine must simulate a "random" deal from a single deck of cards). Look at the pay table from a typical airport VP machine and run it through the EV calculator at Wizard of Odds, or another site. You will see what I mean.