Well made review. Thank you for this! Does the diffusor provide any benefit? I would have guessed it took some brightness. While testing I thought that the cone is well diffused already.
The difference is so subtle , the Osram is just a little bit more precise in the colours and it have a more narrow spot. But it is my point of view. Maybe your eyes will prefer the CREE. If you already have a HC65, keep it. It doesn't worst.