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.
What's wrong with trying Mullard EL34 XF2? I think they are better performing than those you have listed. Second choice would include many other Mullard series and the AEG Telefunken EL34. If you want new and inexpensive, the Wing C EL34 is probably the best of the new lot.

As for input, if you're using Russian 6SN7 then yes, NOS is better. For CJ I would use Tung Sol chrome top 6SN7 and for the 12AU7 position, perhaps the Amperex 7316 or CBS 5814.
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?
I need 4 6CA7 tubes for my MV55
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.
How would this work? And If I wanted to purchase them, how much would you ask?
I was just offering to let you listen and you could buy at Ebay or wherever if you liked the Mullard sound. You would be responsible for shipping cost to and from.

I think they are the best 6CA7/EL34 there is, but unless you hear them you have no way of knowing. Option two is just buy some from a tube dealer or Ebay and have them in inventory.

Mullard will be needed someday, I guarantee. That is if you stay with tube equipment. They work too well in too many pieces to be without.