A_Lee

Absolutely one could if it was a fairly near gate. Even 2 minutes is enough for my typical gate I arrive at (TG), being I walk quite rapidly. If it's the furthest gate, and you don't walk at a fast pace, then yeah, it could be over 5 minutes. But that's not the point at all. I was responding to your statement, "extra 20-30 minutes". Whether you arrive at the concourse or main terminal, you still need to make your way from your arrival gate to the security transfer point, then up to the departures level and to your departure gate. Arriving at the concourse terminal only adds extra time for going down to the train station, waiting for the train, riding the train to the main terminal, and going up to the transfer security point. It has nothing to do with walking from your arrival gate to the area above where the shuttle train is located. That extra time should never be more than 15 minutes for even someone who's slow.

Total time, from the arrival gate to the departure gate could be 30 minutes for someone who walks slow and is at the far end both ways, PLUS whatever time it takes to get through security, which can vary a lot. So taking a random time for security of 15 minutes, and even if your plane "arrives" on time, meaning it lands on time, it might take 10 minutes from landing to arrive at the gate, and figuring you're required to be at the departure gate 10 minutes ahead of time, the total time for the transit is 65 minutes. Being that leaves absolutely no room for the plane being late, or for collecting your onward boarding pass if necessary, it's not a wise connection to make, IMHO. If it was OZ-OZ, then they'd likely look after you, but connecting from one airline to another, you're likely going to be on your own, and OZ won't hold up the plane just because you were late arriving.