Optimised for x4 to 15x. Bob can tell you the optimum magnification (I think it is 6x or 8x). Its not bad, I can't lay my hands on the other test prints I have done at the moment.
Not up to Schneider Apo, or Componon-S 150mm standards, but similar to modern Rodagon and Nikkor 135mm performance. Better than a plain Componon 150mm.