I've done a bit of experimenting, making (yeasted, not quick) breads that call for powdered milk either as the recipe suggests or with regular whole milk. I've usually found that the breads made with regular milk taste better than the ones made with powdered. That said, the powdered milk breads are still tasty, so I do keep some around and use it from time to time.
Also, I want to second VeraBlue's advice: mix it with your dry ingredients. the powder tends to form lumps that can be a pain to break up when you add it directly to the liquids.