Based on the fact that Ratmalana airport is closer to the city centre in Colombo, it can be regarded as a better airport to CMB. It is also cheaper and transfer journey times from the airport to central Colombo is shorter and faster, taxi-train connections take 30 minutes while bus takes 37 minutes. You can use a taxi $5-$7 or Uber $3-$4 for an 18 minutes trip. Ratmalana airport has less queues at immigration, and lower flight delays, it is served by a few airlines with domestic flights and some international charter flights to some cities of the world.