Hi, the Replicant 100 stylus has a longer history than you think. I'm not sure, but I believe it was introduced with the MC 3000 mk2, back in the early 90's. It's a rather complex profile not unlike the Gyger FG1 (and vdHul S1) and usually reserved for their top models, like A90, A95, MC Anna and yes, both Windfeld models. The Cadenza has a Shibata profile stylus on boron cantilever (the Cadenza Bronze has a Replicant 100 on an aluminum cantilever), which will certainly give a different presentation. The Windfeld has Aururum coils (gold plated 8N copper), while the Cadenza Black coil material is not specified (the Bronze does have Aucurum, but based on 6N copper). Within the Cadenza series the main specs (output voltage and internal impedance) of the Black are closest to the Windfeld.
So where does that leave you? Some folks seem to believe that the color scheme used with standard production series like Cadenza give some clues to the voicing within the basic design parameters. The colour Bronze suggests a voicing tailored towards a somewhat darker, warmer sound. Black seems to aim at a more neutral presentation. I haven't heard either, so I cannot comment if that's correct. But based on my experience with other Ortofon models, the best sound is reserved for the 'heritage' models, to which the Windfeld belongs. So I would be surprised if it doesn't represent a clear step up compared to the Cadenza.
So where does that leave you? Some folks seem to believe that the color scheme used with standard production series like Cadenza give some clues to the voicing within the basic design parameters. The colour Bronze suggests a voicing tailored towards a somewhat darker, warmer sound. Black seems to aim at a more neutral presentation. I haven't heard either, so I cannot comment if that's correct. But based on my experience with other Ortofon models, the best sound is reserved for the 'heritage' models, to which the Windfeld belongs. So I would be surprised if it doesn't represent a clear step up compared to the Cadenza.