I think the problem here is that M7's really change over time - they get brighter and lose some bottom end.
When we had Telefunken send us one of their U47AE's I found it quite dull in comparison to our originals (actually JJ you remember I even sent you the files). I had T-USA replace it with a brighter capsule and it almost matched perfectly.
The difference was this: The dark capsule had about a 1.5 dB boost at 5k & 10k. The one that matched our original had a 3dB/3.5dB boost at 5k & 10k. That small difference had a huge effect in "opening" up the u47
Now looking back, I suspect the original T-USA capsule was probably closer to "stock" than the brighter one I replaced it with (although I prefer the brighter one). This is also supported by the fact that Armando (Del Cosmos on GS) received a U47AE with a capsule that matched my "brighter T-USA M7" and he found it brighter than his originals.
I think the problem here is that we are "dancing about architecture". A CK12 can be brighter on top (and should be) than a U47
, but a U47
usually has a harder top than a CK12 - is that sparkly, raspier, brighter, or just harsher?
Technically speaking, I think most would consider a CK12 brighter, or at least more open on top than a normally functioning U47<--- which is a pretty rare bird to find these days.