In MIA (large airport) we walked back and forth and all the way to the end to be told where to check in our baggage. By then, the kiosk wouldn't allow us to check it in. The desk agent was NASTY. She gave us a choice between one of us (only 1 seat) going on the next plane or leaving our bag in the airport. I suggested we take it with us and gate check it, but she said it couldn't possibly fit, and besides security wouldn't let it through. Like I said, NASTY. [It was a cheap bag that had very little in it, since we brought a bunch of stuff to someone. So we off loaded into our backpacks, and left the bag there.] When we got to the gate, we found that the plane was delayed 'by a minimum of an hour.'