if I am going to stain, I like the two step process. I like to do my staining and apply until I get the shade I desire, then when that is done, I will do my second phase the sealing. I always like a satin finish.
My problem is, when you are staining with that combo stuff, and you want your stain darker, how do you get a good penetrating stain when the original coat has poly in it? Never understood that.