NOS GE 6CA7 vs cheaper EH or Winged "C" EL34's


I wonder, regarding EL34 tubes, whether NOS GE 6CA7 (which have been emphatically, and warmly, recommended, but which cost upward of $150 each) would really give better sound than say, far cheaper EH, Sovkeks (New Sensor stuff)..or Winged "C" tubes, the latter apparently being far better. Does anyone have experience in tube rolling this type of tube?
It would be for a Conrad-Johnson MV55 amp (paired with a C-J PV10B preamp).
Also, any thoughts on whether the input tubes would make a significant difference.
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Alberporter: Have you any opinion on the Groove Tube 6CA7 reissues. APparently, they are fabricated on the same and /or similar equipment as the original and according to the same original processes as 25 years ago.
I have some Groove Tube 12AX7's which are excellent for new production. Unfortunately I have not tried the 6CA7 from them. How many 6CA7, EL34 do you require to switch over?
Do you want to borrow four Mullard XF2 EL34 to see if that works magic? I don't want to sell them but at least you would know what to buy.