I find myself wanting a 35mm lens in M42 mount and am considering the available options. The two that occurred to me right away are a Super/SMC Takumar or a CZ Jena Flektogon. If anyone has both of these lenses and would like to offer a comparative assessment, I'd love to hear it. Also, are there any "sleeper" favorites that people have in a 35mm M42 lens? TIA.