Remember, your on vacation, fly in the day before and don't worry about saving $200 and income generated from lost work, worry about the person your traveling with and having a good time. You can save money by cutting back on drinks, gambling and eating out during shore visits.
Celebrity now requires you to agree to the contract of voyage prior to receiving your boarding pass.
You have a deadline on checking in, prior to departure. if you fail to meet the requirement, your stateroom can be taken away.
If your flying from a snow-belt airport and you have a lay-over, your chances of delay or lost luggage is increased.