I have used a semi mounted plough before, but it was a long time ago. I used to have a 3 on front 5 on back ransomes outfit on a tw35. I did a comparison with an 8 furrow semi mounted dowdswell plough on similar furrow widths in the same field. I remember almost having to go down 2 gears to pull the semi mounted. I think I have an old video somewhere? There is no doubt in my mind, its easier traction and power wise to push pull the same amount of furrows, but the downside is, the semi mounted idea is far easier to setup, especially with auto steering!