I wouldnt ever try extra large
Jumped into some random mp today to test it out. Some dude spent 4 minutes on his first turn and then around 3 on each subsequent. Sadly i had elemental near my town and pulled it way too close + lost 2 starting units and 2 settlers, so I just conceded as there was zero point for me to continue.
I would love to play mutliplayer against someone that thinks and acts fast instead of overanalyzing his every simplest move. It isnt chess championship. Other than that im waiting till multiplayer gets out of beta (+next dlc) and maybe i will try to hook up with some people, add them on steam and then start to playing seriously.
I usually play much faster than this guy. More or less 30 seconds each turn. Only when I get lots o cities and a large army, my turns start to take longer. If you want to play, add me on steam. My gamertag is fcm13. Since we both play fast, our game probably would take less than an hour.