i can give you tech info on the units. first both only use mild steel in the heads. the steel is light weight (not thick). this will be problem in the long run. look at the teeth, dont get hungup on the BS of the double sided teeth that you can trun over and adjustable motors. look to see how much larger the tooth than the tooth holder, the more tooth past the holder the more protection for the holder and drum. ask if you can talk with a tech or engineer at if you need to can you get a direct number to tech or engineer for help if the dealer cant help you. how long have they been making muching heads and the number of different heads do they make. given the facts and not the BS i would be looking at FAE or Fecon.