I think bags are so individual for each person. A "designated carrier" for a family of four with teenagers is going to be very different from a family with a babe-in-arms (big old diaper bag anyone?) is going to be different for a couple with no kids. Someone into photography (I need my lenses!) is going to be different than someone into scrapbooking (where to tuck all those little scraps of paper and souvenirs to keep them safe). And so on...
So I think a little bag-user profile would be helpful!
I am married, no kids, 30-something who likes to travel as light as possible--especially in WDW which is SO HOT AND HUMID that hanging additional things on body can be downright uncomfortable. One requirement was also that it be neutral enough in its styling that my husband could carry it some of the time when I needed a break. I am not the designated carrier, I am a part-time carrier.
So my go-to bag for WDW (and I used it on my cruise) is the Overland Equipment Placer:
http://www.ebags.com/product/overland-equipment/placer-shoulder-bag/140201?productid=10155764
It holds an insane amount for its small size. It could carry a point n' shoot camera, a cell phone (or wave phone on cruises), sunglasses, notepad with pen, my lanyard/small group of trading pins, a travel size sunscreen and lip balm, park maps/media, small purchases (such as shot glasses), a small bottled water, and the requisite cash and cards. And would still have room for a bit more if I needed it.
It was never bulging, never too heavy, easily tucked away as needed in a locker, or between my feet, or in a safety bin on a ride (like the netting compartment in the side of Space Mountain, or the center waterproof area on Kali River Rapids). Strap could be adjusted for cross body or shoulder, and even could go cross body on my big hubby. Win-win.
Here is me with it on deck on our Alaska cruise earlier this month. Turned out this was the only day I really used it on board, and only took it off the ship twice. I didn't need to carry much around the ship, and on our two excursions hubby was bringing a backpack with our rain jackets anyway. Our two non-excursion days it went with me to carry the vitals. You can see in this pic that instead of carrying a lanyard, I pin my traders onto the front flap--works great and cuts down on things hanging around my neck.
I think I remember they handed them out once you got off at CC then you returned them before getting back on the ship.
