Although it's a bit annoying not getting to select a time, my experience from the other 10 cruises on X we have taken since September is nobody really cares. We just show up when we feel like it and get processed through with no issues. Sometimes we are early, sometimes we are late. If you have the earliest time, be prepared for the ship to get cleaned and cleared so you may be waiting upwards of an hour. For suite guests, that is no issue because they have a catered waiting area, for others, it's just hurry up and wait.