I have the 8 inch model. It is not a true helix head and there are fewer cutters,, but probably better than knives. I generally have been pleased for what I paid. When edge jointing you do need to pay attention to position of fence and the first cutter. I tore up some cherry before I realized I needed to center the board over a cutter. There is some space between cutters. It is fine for shorter boards. I gerryrigged an outfeed support to try to improve length of boards i can run. If you have the extra money get the 8 inch model. For longer boards I get better results with router table or glue ready blade on tablesaw. Can send you a pic of my setup if desired