I noticed quite a bit of complaining about the lack of slots. While this is true at airports such as JFK, LHR and HND, this is certainly not true game wide.
Right now PHX, one of the US busiest, is wide open. Brazil has one of the best aviation markets in the world, with dozens of markets that can support multiple airlines and frequencies, yet few players choose to base in GIG, GRU, BSB or in neighboring EZE, SCL. I am in SMF, a smaller airport in California, but the city has numerous markets with over 100 daily pax. Same is true of SAT and AUS.
Players need to be more creative in picking markets and hubs and shy away from hubbing in the biggest airports in Europe or North America.