My neighbor has two and they are difficult hens...
Out of their flock of hatchery birds, the Delawares are mean picking on others even during free ranging, they want other hens to leave the whole area when they find some goodies. It made chicken sitting more difficult than it should have been due to the feeding situation. They are rather loud about egg laying compared to the others (buff orps, red sex links, easter eggers). Also have a tendency to hop fences... we had to add more height to the border fence to keep them out, during the short time they were getting in they would go after our chickens with a vengeance, and we would go in to get them out and find the wily things ducking and diving and doing everything they could to avoid being shooed out the gate.
I just asked my mom if I forgot anything and she said "make sure you say "stubborn, greedy, determined" lol.
The line probably matters a lot, these are hatchery birds that are clearly scrawnier than breeder stock. Maybe the line you're getting is different.
Disclaimer: I have a docility bias as I've selectively bred our whole flock for gentle demeanors.