Most people agree that the ofna 086 makes a bit more power then the Dynamite 086...The Dynamite 086 is (a lot) more durable tho. Especially the hardcoated one. Something to keep in mind aswell
edit:
part of the difference in the Ofna and Dynamite pipe is the Ofna square header that comes with the pipe. I would get a compete set (either Dynamite or Ofna) both can be had for $ 55 or less a set at A-main.