The dice are on the smaller size, but they're made of the same material as the discs (bakelite?) and, in my opinion, have a nice weight to them. It was the first thing I noticed when I played the game.
Everything about the 2 included dice (size, color, weight, feel) seems just like many other dice I've picked up over the years (e.g., Nestorgame's "Gardens of Mars"). Basically, nothing special here ... very unlike the dragon pieces themselves. I believe the dice can be safely swapped out without losing any synergy with the rest of the components, and I have, in fact, done so.