I have a few experiences behind myself of comparing various types of the Kontrapunk b, these experiences are shared in other threads.
These have been original spec' with a usage life between 300ish - 1000+ Hours. Other models compared have been with a retip and a full rebuild with uprated Ortofon parts and Ogura Beryllium Cantilever with Ogura Vital + Styli.
A Selection of the above have been compared to a Windfeld and the Ortofon Vienna, of which the Vienna is quite a rarity and has been described as the fifth member of the 'bach' family of Cart Models.
The demo's have all taken place on a set up that has the same Headshell Material, TA>TT and system.
The general shared thoughts as a outcome of comparative demo's has been that a different styli, is not too much of a impact on a sonic. A detail retrieval might be detected as having a difference, and compared to a original styli, the other styli in use, certainly refined the presentation, which is a more attractive experience.
The general shared thought between attendees at a demo' has been that the structure of the Signal Path of the Cart', is seemingly the area responsible for creating the most noticeable change to a Sonic.
The original K'b to a retipped K'b are very very similar, even though the FGS Tip is a refined experience and worth consideration at the time of a retip, certainly more attractive than a original with a longer usage life.
The rebuilt K'b jumps out in front and sits very well in the Company of the Windfeld and Vienna.
Aucurum Wire is rosy in tone, when A/B compared to the Vienna and K'b Silver Coil Wire.
There is not many who would give the Windfeld a description as being rich, but in the company of the K'b and Vienna, that is how it comes across.
The Vienna had a FGS and the Windfeld the Replicant, I did not see the Tips being responsible for the differences in sonic being detected.
It might be the Aluminium Armature and Silver Coils on the K'c are the parts that create your X Factor. The Aucurum and Aluminium Armature on the C'br, might not be your attractor.
I would seriously consider the FGS for your Aluminium Armature of the K'c, if the marriage is a compatible one, as a exchange tip on a K'b, it substantially tidied up the presentation over the originals.