I have not booked on a competing line yet, but I can understand why others are doing so-- especially if you need to hit school break or popular periods, the best rooms on other cruise lines get snapped up and generally pricing tends to go up as categories are closer to being filled. It used to be on some lines you could book dining and shore excursions as soon as you made the deposit-- so there are definitely advantages to booking early, and we're now barely over a year out!
I didn't get the email re: Galveston sailings, would someone mind sharing what that promo is?