Certainly (but this is to be expected for a lens 1.5 to 2.5 stops slower...) Test that I've read indicate that the Heliar shows, wide open in the corners, in excess of 100 line pairs per mm resolution. The Zeiss Sonnar is a special, "characterful" lens, but I doubt it could compare at any aperture to the Heliar, for any parameter if technical image quality. You just can't make a f/1.5 lens compete with a f/3.5 lens.
Originally Posted by ntenny
It is basically completely flare-free, i.e high-contrast edges (as shown in some of my images) are rendered perfectly regardless of lighting or intensity.
Hey - it has to do something special for being only a f/3.5 lens :-)