Dullcote is definitely flat. If you're lazy (like me) use the spray cans, put it on nice and wet, and it will level itself off just fine and give an even finish.
Some people complain about splotchiness, but I only had that problem when I was trying to mist it on with the cans. The nozzles aren't good enough for that, so just soak the model and let it do it's thing. There's very little carrier, so when it evaporates your details won't be obscured.