Assuming you a first time cruiser? If so you may want to do it if you're really worried about a particular excursion or want an early Port Arrival Time. Platinum and Gold level
Castaway Club members are able to check in quite a bit before first timers, so if something is limited availability or very popular, it benefits you to try to book ASAP when your window opens. Otherwise it's probably not a big deal at all to wait until morning. Remember, check-in is 12 a.m. Eastern Time. Hope that helps! Have a great trip.