Well, it depends on how picky you are on stems and buttons.
As Sam pointed out, Castello uses acrylic and Dunhill vulcanite (overall, I prefer Vulcanite).
Most new Castellos have pretty chunky buttons.
Last year, I purchased a new Castello and a new Dunhill (both bulldog shapes,same physical size). Both are terrific pipes, but I reach for the Dunhill more often because of the more comfortable button. I supposed I could fix the Castello, and I just might.
Other than the button, it's a toss up for the other features. (Castello Trademark vs Dunhill Cumberland)