I'm a big fan of the shorter mini trip to the theme parks. But that's probably because it's just me and DS that like the theme parks. I just love going with DS, but for me a couple days is perfect/magical, but I'm not inclined to do more than three theme park days. For our main family trip each year we do something that we all love including DH and that's usually a summer trip to the mountains. DS is 20 now and lol and we are so excited to be doing our first Disneyland trip in January of 2017. He has been to WDW 15 times, but never Disneyland and would really like to see the original park Walt put together. We'll throw in some thing in LA/Hollywood too, as although he has been to New York City and Chicago multiple times and London once, he has never been to LA and would like to see the be a tourist in LA/Hollywood too. So our next trip is a mini four nights/four and a 1/2 day get-a-way to Hollywood/Disneyland.
For us it's just way cheaper to do WDW (air is about $150 pp less). We can get great deals on offsite condos at WDW -- much less expensive and much nicer than the good neighbor hotel suites (although being walking distance to the parks will really be great. We don't know what we are missing on that yet.).
I too am one too that loves to do a vacation or two or a vacation and a mini trip every year, but I don't want to have to penny pinch to do that, so tend to be happier with a more modest options that fit easily with my annual vacation budget vs. putting aside what seems like an obscene amount of money for one trip. That's just me though and I do have a bit of a bean counter personality -- am into budgeting, tracking expenses, savings goals. Lots of people have bucket list places. That's not me so much. For me where I go is just really more of a back drop for having some fun with family or extended family. (e.g. We are going to Colorado and hanging in the mountains there rather than an Alaskan cruise or cruise tour, for example, and I can cover three great mountain based trips -- Colorado this summer, South Dakota summer of 2017, and Bar Harbor/Acadia summer of 2018 for what one Alaskan Cruise/Cruise tour would cost.) We did a few years back let DS pick a place to travel to for high school graduation that would be a little more exotic and higher priced than our normal main vacation trip and he picked Kauai, HI. It was really, though, just the air that was the killer, and the trip was about $2300 more than what me spend on a week long trip typically, not that much over the top.
With six of you your air is a real budget buster and I would in your shoes be really tempted to do some driving trips if they were things that sounded like the would be fun options that we could all get excited about. // If you are all, though, really keen on WDW it's definitely your choice. I've been there, done that, and already bought the T-shirt, so not really in your shoes.