Hello Nestor, Actually it's been kindof entertaining debating cornerbead ins and outs. I guess we'll have to agree to disagree on this one. It seems your biggest hangup about metal is the dent removal problem so let me reiterate the best ways to do so. I suggested tin snips mainly because this is geared toward homeowners and the tools they have available. For smaller dents I like I said tap it from the outer edge of the dent til it is straight then recoat it. For significant damage you have to remove the damaged area and install a splice piece. To cut through the bead above the damage for removal there are many different methods. Tin snips do work and the ones I use personally aren't as big as the ones you have pictured but do flare the corners when the cut is made you simply fasten them back down and add a splice where the damage was making sure it is straight with a level. But I prefer to make the cut with either a small cordless metal saw or a hacksaw. And I think everyone owns stapler or at least should. Also I prefer staples for fastening mainly because screws tend to warp the bead and don't stay as flush to the drywall making coating more difficult.