Another option to consider. A little background info: We have 5 kids -- now all adults -- but we've been taking trips with them since the oldest was 11. The youngest age we've ever taken our kids on a Disney trip is 4 (we had a rule about not needing a stroller and scheduled naps, and they had to be at least 40" tall so they could go on most of the rides). We usually go for a 7-night/8-day stay but leave at 6:00 a.m. on day 8, so it's really 7 days for us (or technically 6.5). We used to get 6-day parkhoppers and would just hang out at the resort, ride the monorail, go to DTD/DS, etc. on our arrival day (we drive and usually arrive between 10-11 a.m.). Then one year we booked under a Buy 4/Get 3 free deal for resort and tickets. So now we had an extra day of tickets. We took advantage of that and spent a few hours at EP on arrival day -- headed over around 3:00, did some rides, had dinner, did another ride or two, and then headed back to the resort to get to bed at a decent time so we could hit the ground running in the morning. Disney's little "trick" worked. We've bought a ticket for arrival day for the 7 trips since that promotion. The cost to go from a 6-day ticket to a 7-day ticket is about $25. To us, it's totally worth that extra $25 to spend a few casual hours at a park (usually EP) on arrival day. It allows us to ease in to our vacation and get some things done at one park. That way we can have another sleep-in day during the week when we return to EP because we don't need as much time to do all the things we want to do since we've already done several things on arrival day.
And after several trips of allotting a full rest day in the middle of our stay, we also quit doing that and started buying tickets for every day of our stay. We found that we didn't really want a full day away from the parks, just another day to sleep in. Having tickets for every day allows us to go at a much slower pace throughout the week. We do mid-day breaks on the days we do rope drop (at MK, DHS, & AK -- haven't done rope drop at EP in years) and then either return to that park in the evening or go to a different park. The rest of the days we can sleep in a bit (or a lot) and just arrive at a park late morning/early afternoon...or sometimes not until late afternoon.
We've done the short visit to a park on arrival day and no full rest day method since our 3 youngest kids were 4, 7, & 8 years old and it has worked really nicely for our family. We actually find this method less exhausting than doing long park days and having a full day off in the middle of the week (we found we always wanted to be at a park that day anyway). I'm not saying this works for everyone because everyone's kids/family are different. Just another option to think about.
