EL34 vs 6CA7 vs KT77

I am looking to do some tube rolling soon. I currently running Winged "C" EL34s and like the sound overall. The "C"s have good balance and a tubey sound but could be tweaked here or there. Any suggestions or opinions on the EL34/6CA7/KT77 tube family is welcomed!
I replaced my VTL st-85 EL-34's with Shanguang treasure 6CA7's
They are pricy but with much more resolution, dynamics and frequency extension than the EL34's
When I had an EL34 amp the tubes I liked best were vintage Tesla (not JJ) and the Siemens RFT. Of course, I didn't try every tube out there and both those kinds would be pricey and perhaps hard to track down.

For new production, I had the same Winged "C" tubes as you and liked them. I was extremely happy with a quad of reissue Genelex KT-77's from Jim McShane. If I got another EL34 amp I would buy the Genelex again and not spend the money and effort tracking down NOS.
I have some of those Siemens. They are sitting on the shelf while I use new production EH 6ca7 daily, because these are cheaper and don't do anything I find offensive. I don't really find much to get excited about the NOS Siemens, but amps are different. I haven't tried the Genelex or shanguang.
In my VAC PA 35.35, I was using "Winged C" and EH Gold Dragons. I swapped out all the tubes at once, the smaller tubes are now NOS Telefunken 12AT7 and 12AU7. The EL34's are Mullard reissue with the Groove Tube label. The change these tubes made was amazing, it transformed this old amp from sounding ok, to an amp that is maybe the best I have owned, and one of the best I have heard.

Best of luck,
Mtb ww - I have compared Winged C EL34s to EH 6CA7s in Cyber Consonance 800SE monoblocks. To my ear, listening to Totem Forest speakers, the Winged Cs seem to have a little more warmth and possibly a tad more bass depth but the EHs seem to present a larger soundstage with more air and upper frequency extension. I will probably switch betweeen the two from time to time but right now I'm listening to the EHs. I expect results will be system dependent.
Sfar, I know this is a very subjective question, but how would you compare (tone, soundstage...) the "C" EL34 to the KT-77s?
The Siemens you can get from RAM Labs are the best I have heard on my Music Reference RM9SE, but purely on hearsay, it does seem there is a lot of good feedback on the Genalex KT-77 reissues. Oh, you are right, it is not only subjective but perhaps only valid within the context of a particular amp driving a particular speaker, you really do have to try them to really know. I would call Jim McShane who listens to alot of these variants - he really does like the Genalex though....
Mtb - you're right, the choice of tubes is both subjective and system dependent.

I'm not sure if my description would be helpful to anyone else but I found the Genalex KT-77's to have the same kind of musicality as the "C" El34's but they seemed more articulate, if that makes any sense. That applies both to the PRAT and to the soundstage. They just sounded right, more transparent without losing any of the sweetness. I'm afraid that's the best I can do and even that probably isn't all that illuminating.

I was using the tubes in an AES AE-25 Superamp in triode, driving a pair of Devore 8's.

I did take acetone and a paper towel and remove all the swirly red and gold script on the glass of the KT-77's, after which they looked like proper tubes rather than something you'd find in a New Age candle shop.
Thanks Sfar, that help greatly. Have you (or anyone else) had experience with the JJ KT-77? I heard the reliability of these tubes has bettered since their initial release. Would love to get the Genalex KT-77, but the price point may become an issue.
Jim McShane sells them both, and has many buyers of both - his advice is worth seeking, as well as the fact that he matches tubes very well and sell at very competitive prices. He is especially useful on issue related to reliability since he sells so many sets - he's been known to stop selling tubes that have "problems" in the field.