I fitted a Holga, fun plastic (Cult) Lens on my Sony a7 and I'm very pleased with the result
Some results from an afternoons walk about with the lens and camera
Results from the Holga would not be to every persons taste. But it is a unique look
Since these shots I have used the lens for fun portraits and glamour with pleasing results.
IMO a mirrorless full frame camera is fantastic for the lens.