Frankly, I don't know what's in a CK4, I assumed it was a Teflon CK12 (the new ones) or maybe a CK1 - that's a good place to start getting information straight. The lollipop gets you cardioid only, no figure eight. With the C28, C60, 451's system, the capsule provides the pattern.
The B6 is the CK12 copy, I'm pretty sure, mine is older and isn't marked. I have the B7 as well, and that's a cool capsule. While your at it, you better find an A51 knuckle sometimes these don't fit as well as you'd like and the knuckle always seems to make it work. I've never heard the B2.
I have 2 C28's with lolli's and a well traveled semi-famous LA veteran guitar player thinks these record him the best ever. I think they really sound good.
Here's what I can guarantee you. The CK4 with the original capsule inside on a C60 with never be mistaken for a E Lam 251 by anyone with ears. You probably won't fool a Pro with a B6. You might have a chance with a lolli with a good CK12 brass inside on a C60 - that's something I'd like to hear. Keep in mind the C60's goal is miniaturization, that might cause a breach of quality in a clone.
Good luck
Terry