Gbm,
I am not looking for the perfect outlet nor really find the "One" that promises to be the last in outlets.
I merely try my best to find the strengths and weaknesses in the outlet.
I agree and find the black still a very good outlet, but knowing the upper midrange doesnt come alive, without comparisons it actually will sound very good and most will feel nothing ever was lacking.
I did'nt have a choice but to reintroduce the GTX (non-ncf) connected to the p300 and as with my previous conclusion and what your impressions mirrors, sound a not as clear, open overall and slightly warmer than i would like. This certainly would suit a dull system or one that needs more upfront clarity. The black would be e best bet on a tube or warmer system even better.
However, the areas which the black lacks, the GTX shines.
The GTX however remains in my distributor but now connected a non audio chain equipment (Telos Q Noise Reducer), in doing so, it has reintroduced that slight bit of upper midrange onwards brilliance and presence back in the system while not sounding a bit fuller or warm , which is also not my preference. Just for example, if the black was a 5 on the warmness scale, the GTX would be a 7.5 to 8 where my preference would be a 6.5 on this scale.
To highlight, the Furutech's are pure copper, you will get a purer, clear, organic and warmer sound which are traits of copper over brass, period. The brass contacts of the black outlet will never provide sonically what a pure copper plated connectors bring sonically to the table.
I also find that the SE is still a good outlet overall and and has many good qualities which might also be easier to fit into the majority of systems over the black outlet, which may sway too much leaning out the sound.
The black outlet does sound thinner and on certain few recordings, bass weight can also seem to vanish.
Moving away slightly from this topic, i did also purchase a NCF inlet, but it is slightly wider than the standard iec inlet and was not installed as enlarging the casing is required. As NCF is made of nano crystalline and carbon in the mix and affect emf, it now sits between the heads of 2 cables come out from the p300. Holy, it affects the sound using it this way, it adds a wholesome organic and further delicate smoothness to the sound, this complements what the black outlet does'nt provide in it's sonic presentation.
Strangely used, but the inlet stays sitting there between the 2 connectors!
There is something to further experiment with the NCF mixture, it is actually very potent sonically, with or without the copper rhodium contacts.