We're going on the Harmony in April 19. We already had internet for two so it was worth canceling and upgrading for the added cost.
One thing I read was it states reserved priority seating with no reservations required. I believe I'm reading this correctly. Everything I've found posted stated reservations we're still required. Maybe they changed it, but if this is true that is a huge benefit not having to plan out shows and go more "on the fly"