I also prefer a chisel. Moldboard's have their place but they are tricky to use. You have to really pay attention and have them set right or you can screw things up in a hurry. They are directional and you also have a dead furrow to deal with. Not that they are rocket science but they are not like a chisel where you just hook it on and go. With a chisel it is not a big deal if you make overlaps or go different directions or whatever.