Just yesterday developed my first silvermax in HC-110 (dil. B, 7min @20C). Looks like APX-100 (as mentioned above by piu58), consistent with the similarity in the HD curves. Really "shines" in scenes with high dynamic range, combining sunlit and open shadow parts. Presumably the character of the images is more correlated with the emulsion than with the developer. Strange statement found on the fotoimpex site: "SILVERMAX is only available as a 35mm film and will not be manufactured in other formats"; a pity, might change if sales reach sufficient volume.