I'm on the fence about it. We've always bought hoppers and in the last five, or so trips, only hopped like once a trip. We now have annual passes this year, so it's got a built-in hopper, but I don't know if I would buy hoppers again unless we were going to be there more than 7 days. Like someone else said, the time investment of getting out of one park, traveling to another and getting into it deters us.
Don't get it and decide whether or not you want it when you get there. I believe it's a flat $50 per person to get it, regardless of the length of your ticket. So if you're going to get it, it makes more sense to get it early in your trip. You know?
Have fun!!
We've done the same... become annual passholders, but every other year. We get at least two trips out of them this way. So if we buy APs in August one year, we'd use them again for the next year's trip in May or June or July. The fact that the hopper option is built into the AP is a big plus. And sometimes AP discounts on resorts for the second time around would make it even more worth it.
I think park hopping is useful for a shorter trip... like you didn't get a chance to experience certain attractions at MK on your MK day, but you finish early at AK on your AK day. So you can go to MK later that day. Of course, the down side is that it is quite expensive to add $50 to a ticket that's only good for three or four days!
If you're going on such a long trip, as it appears that you are, you may not need it... just plan your days well.
And in a sense you still could park hop, but to the water parks and DQ...
You could start a day at MK, take a midday break at TL, then return to MK later. Or you could start a day at BB and finish it at DHS. Just remember that you
can't do this
every day. But even with our APs, we don't park hop between the four parks every day.... we probably do it just a couple of times.
If we were going without APs, we'd look at it like this:
is it worth the extra $200 (4 tickets in our family x $50 each) to just get a couple hours at a different park on a day or two of our trip? Probably not... just plan better. If we're done with a park for the day, we're done with that park! If we're tired, we would just take a mid-day break and return to the same park that night.
You could also get a change of pace from the parks by exploring different resorts, strolling the Boardwalk, checking out Downtown Disney, or even just swimming at your own resort pool. You don't have to have a ticket or park hopper option for any of those activities! With all these options, park hoppers are less necessary!
If money is no object, go ahead and add it, just for the flexibility. If you do care about keeping costs down, even just a little, then skip it! Park hopping is not necessary.