I love it when the leg elastics go all the way up in the back. I like the way it makes the butt poke out a little bit, and creates ruffles around the legs.
A lot of adult diapers don't have this. The leg elastics end right at the bottom of the butt, and it creates this rounded, bowling-ball effect. Some people might like that, but I like the butt of my diapers to poof out a little.
It's a weird little quirk, and I may be the only person in the world that it matters to, but for whatever reason it's an important part of diaper-wearing for me. I love it when I find an adult diaper that has that kind of elastic in the back.