I currently have a JD 3 bottom 18" mold board plow. All my fields surrounded by fences, and it gets real tight alot of the time. I have found a JD 3 bottom mounted roll over plow. All I have ever used is a semi-mount how do the two compare on plowing. I am really tired of having to plow one side of the field and then go to the other side and plow takes up alot of time and diesel. Also hate the huge valley you get in the middle of the field when your done, and then I have to take more time to fill the valley in by going the oppisite way and ending up with two small furrows that I can fill in with the disk. I am pulling it with a kubota 9540 4x4.