I get a lot of mileage out of the slow "check" on a coordinated board. If it coordinates on the turn, and I want showdown, I slow check to feign a slowplay.

In contrast, if my draw completes, and I do want to slowplay it against an aggressive opponent, I don't check fast or slow. I check steady. Anything that alerts my opponent is bad in that case obviously.

As for quick calling, I don't respect it at all. I bet into you until I find resistance.