Been going back and forth for the Voigtländer 15mm III f/4.5 Wait for the native E-Mount (have EXIF data and electronic distance scale) a bit lighter and smaller OR Get the Voigtländer M-mount now with adapter (which one? Metabones Novoflex??? ) =cheaper? depends on adapter and the deal of the lens no EXIF ; no electronic distance scale in camera, would be a bit larger and bit heavier But perhaps I would be more flexible in the future if a different camera manufacturer one day surpasses Sony I could ALWAYS use the M mount with another adapter Also could use the adapter for other M-mount MF glass in the future if I want another lens.... just get then the other M mount again? Is M-mount popular? Heck its been around since 1954!