With a coated knife, you are not guaranteed any sort of finish under the coating other than the minimum necessary to put a coat on. You might find grind lines, 'infi dimples', or a nice, smooth finish as some people have when they've stripped the coating. Coated is cheaper because there is no need to put extra effort into finishing the steel.
DC (double cut) is a specific finish to the steel with a bead-blast finish that leaves an attractive (to some) matt effect. Personally I do not prefer it because it is the most rust prone due to the increase in surface area from all the micro-indentations from the bead blasting.