We never go on check in day. Even the one year when we arrived just after 3 pm at our resort and the parks were open late, we opted for DTD to start off. I am with you on this one: not the best use of a park entry if you have days to spare since you don't get that many hours out of it, especially with the arrival times of most international flights.
Catherine, Obligatory VH meeting? THey can surely not force you to book a holiday with them and then spend one of those days listening to their promotional bumf!