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.