EL34 differences in air & stage depth?


I've been searching the threads trying to learn about differences between different EL34 tube offerings. Most comments seem directed at tonal qualities. I'm curious if any have compared and found differences in "air" and stage depth. My system is posted. The H-1 appears to come with Shuguang EL34s. It does many things well but I'd like a little more openess in the presentation. Possibly this means more mid-range forwardness and/or greater high end extension. Thinking about "tube rolling" (KT77s as well as EL34s). Any suggestions would be very much appreciated. Thanks in advance for your input.
128x128ghosthouse
Joe - Thanks for the input. Albert did mention SED Winged Cs as the best of current production EL34s. I'd also seen many positive comments on these. I do appreciate your input on the EH and the GT Mullard clone in particular. The concept behind the GT xf2 Mullard sounds like a winner (but I'm gathering execution falls short?). With the possible exception of the Siemens, I probably won't go NOS. Still bouncing around mainly between Winged C, Mullard re-issue, and Gold Lion KT77.
I have the SED Winged C's in my VAC Avatar. They are many strides ahead of the Shuguang tubes imo. I would like to try some of the NOS tubes I read about but they would burn too big a hole in my wallet if you know what I mean.

I haven't tried any of the other EL's mentioned but the SED's seem to have concensus on this and other sites. That helped me with my decision and I have not thought about changing.

I also changed out the 12ax7's and 12au7's with NOS Bugle Boy tubes. Thay made a remarkable difference as well.

Good luck.
Thanks, Bj...I can say for sure, votes for current production EL34 favor Winged SED heavily. I'm with you on $ expenditure for NOS. The Siemens are within reach but even here I'm a bit confused and seeing pricing that seems to vary from $225 - $300+ for a quad. Seems like Siemens mftd. for different brands as well. Plus I always think about needing spares or another quad in the future when maybe the supply picture has changed and availability is even worse than today. Good current production (if there is such a thing) appeals to the pragmatist in me.
To all who replied...Thanks for your input. For various reasons (not just cost)...I decided to go with SED Winged C EL34s. If these don't get the job done, I'll give further consideration to the Siemens NOS option. What I've leared that complicated that choice is the range of "Siemens" NOS tubes out there.

I found this link, enlightening:
http://www.tube-classics.de/TC/Tubes/AudioTubes.htm
Right now I´m listening to a Harma EL34 quad in my Leben 660P amp and they are fantastic and they are cheap. You can find them in Watford Valves from UK.

I second the Electro Harmonixes are very good too.

BTW, I´ve been trying other Harma tubes (KT-66, E34L, 5881) and they are great.

Greetings from Spain.

Daniel