There can be a disadvantage in checking early.

From experience:

• If the flight is overbooked, it is possible that you will be upgraded to business if there is no seats available in economy.
• I had a flight where the airline seated everyone packed at the back. By being VERY late, they gave me a nice seat in an empty row.

This is pure gamble tho.

There can be an adventage in checking early.

From experience:

• If the flight is overbooked, it is possible that you will be upgraded to business if there is no seats available in economy.
• I had a flight where the airline seated everyone packed at the back. By being VERY late, they gave me a nice seat in an empty row.

This is pure gamble tho.