We were last there before metal detectors, but I can attest that going bagless means less to deal with, end of story. Getting through security, if there is a No-Bags line, is ridiculously faster.
We use cargo shorts and minimalist packing. A little RFID-blocking pouch holds a DL, CC, enough cash to get us through the day should the MB system go down, and a reloadable Disney GC for keeping spending under control.
My cell phone goes in my pocket. His goes in his. He also gets to carry the charging stick(s) unless we'll be back in the room mid-day. He also carries the small bottle of sunscreen. If we're feeling particularly brave, each of us grabs a granola bar. We get water in cups in the parks and generally get our food from the parks.
That's all we carry, because anything more gets in our way. Granted, we don't have kids with us, so YMMV. The feasibility of this goes dramatically down once you have kiddos and they have needs. I would still make note of comfort stations and do everything possible to minimize carry in the parks. The more you carry, the more you have to figure out when it comes time to go on rides, wait for parades, or discombobulate/recombobulate and there's a real time-spend there.
