Paper-faced beads are the way to go. I avoided specifying them for years until the rep for US Gypsum set up a sample for me -one corner with standard metal bead, the other with paper-faced bead. I beat them both thoroughly with a 2-lb hammer. I no longer allow metal beads on our projects. (The paper-faced also installs easier, for less cost.) Use USG's "B1XW EL" or No-Coat's "Ultracorner." Another brand is "kwik STICK" but I haven't used it.