If you arrive at 8:05 you will be seated. You are in the first group for the day. They spread out the times so that everyone doesn't arrive at the same time.
However, I find with the early morning reservations, many people under estimate how long it takes to get there or have trouble getting their family out the door.
If you are one that can get everyone together, then get there as early as you can so you can be done before rope drop.
Bonus** First Princess to Check in is generally Princess of the Day and gets a special announcement and escort up the stairs.