That's actually a variation. It's marketed as the "deck of dice" or something like that. Essentially, you're making random draws from the set of all 36 outcomes when rolling two dice without replacement, instead of with replacement. I'm not sure that leads to sloppy habits as much as it encourages card-counting, which isn't that strategically interesting. But since Settlers is a game of exponential growth, it does avoid the problem where 11 comes up five times in a row near the beginning of the game, giving one player a huge advantage.