The Ultrafine stuff is made by Harman, if I remember right, which is part of Ilford. It seems to be a more flexible film in terms of contrast and detail, whereas Arista is like Fomapan 400, a very contrasty, grainy film with a distinct look. Ultrafine will probably be more versatile, but that's not to discredit the look and feel of the other one, if it's what you like. As mentioned above, Foma (or Arista) 200 is a more subtle looking film even shot at 400 and processed normally. It (the Foma version) is the first film I've bought a 100' roll of, and I'm enjoying it quite a bit.