I just scored two cheap seats on America West from SFO-LAS. The assigned two seats aren't next to each other, so I called to see if they could reassign the seats. The agent told me that there is only one more seat available both ways, but if we get to the airport early on the day of my flights, we might get reassigned to two seats next to each other, as America West holds 20-30% of seats on each flight and doesn't release them until the day of the flight. She explained that these are exit row seats, handicapped seats, etc.

But can these "special" seats really make up 20-30% of the whole flight? And if she saw only one more seat available on the seat map, does that mean only one more ticket is available on that flight, or that there are more seats available, but the seats won't be assigned (not even the undesirable middle seats like I got) until the day of the flight?

Does anyone have experience getting seats reassigned the day of the flight and how early should I show up for them?

Thanks!!