There is one decisive advantage to the Z-mount version, and that is the price.
M-mount Version ist almost twice as expensive as the Z-mount version.
If you factor in the cost of an adapter, it's probably more than double.
At least here in Europe, the Simera 28mm f/1.4 for M-mount costs €673.95, while the Z-/E-/RF-/X-mount versions costs €349.95.
The niche market for a manual focus (MF) non-CPU lens like this is so small that Thypoch has to offer much larger discounts to attract new customers than they would for the M-mount version.
Therefore, for me, it was a no-brainer: at the price of the Z-mount version, the Simera 28mm f/1.4 silver was an absolute no-brainer.
The niche and therefore demand in the E-/Z-/RF-/X-mount is so small for such a non-CPU MF lens that Thypoch has to offer much larger discounts to generate new customers than in the M-mount.
For almost €700, and the added cost of an adapter, I would never have become a Thypoch customer.
If a portion of this small niche also opts for the M-mount version for their Sony E-mount or Nikon Z-mount bodies, this drives down the price of the E-/Z-/RF-/X-mount versions even further, because Thypoch can only generate demand outside of the M-mount by offering massive discounts.
However, if you already own other M-mount lenses, or want M-mount only lenses such as the Simera 21 or 75mm f/1.4, then the answer is clear.
