I agree about the "fuzzy" -ness about what was rolling out between 1994 to 2003. My only caveat was based upon the notion that 1994 was the start of the changes that were being made to the DCU, both in mechanics (i.e. the introduction of Hypertime) to individual origins (hence, issue #0, or even whole-sale reboots like SHAZAM!). And I also thought that this was the time when Superman was totally divested of having any connections with the Legion of Superheroes, having been replaced by Mon-El (or, "M'onel"). That's why I felt strongly in creating this thread (and, again, I used "Zed" as code for the Zero-Hour iteration). I know that I seem to be stepping on your toes about these discussions, and if I did, I do apologize. It's just that these sorts of discussion, particularly DDC#12 gotten me so...geeked out about it. But, by all means, this thread is yours (if that is even possible). Peace...
To the extent that anyone owns a thread, agreed. dswynne has nothing to apologize for, and no toes have been stepped on. I will say that just before I first posted to this thread, I had been getting ready to start a new one of my own that would have been called “Earth-τ: what would you like to see?”; but then I saw this thread which covers the same ground, so I went ahead and posted here. That said, the only reason I was thinking along those lines in the first place was due to dswynne's comments in the Earth-Σ thread.
Really, my only quibble is with the name; and ultimately, that's not a big deal.
Rogue wears rouge.
Angel knows all the angles.
On Earth-Σ, Superman wasn't connected to the Legion of Superheroes, and Valor was substituted for him as the modern-day inspiration for the Legion (Valor being the codenames that Mon-El was going with at the time). So that's not really a substantial difference between Earth-Σ and Earth-τ. The nature of the Legion that got inspired is very different, though; and as you say, the Shazam aspect of the DCU got a reboot.
As for the #0 issues: unlike the #1 issues that came out at the start of the New 52, the vast majority of the #0 issues didn't actually redefine anything; they were “merely” issues designed to be jumping-on points, sales pitches to potential readers designed to tell them who these guys are, where they come from, and where they are now. All of the big changes had already happened by then, and Zero Hour (and the subsequent Zero Month) served to tie it all up into a pretty package. That's why I think of Zero Hour as the “end of the beginning” rather than as the whole of the beginning.
But really, that distinction of the beginning spanning from Armageddon 2001 to Zero Hour affects Earth-Σ far more than it affects Earth-τ: all of the things in that 1991–1994 window happened on Earth-τ. My contention is that I'd prefer to say that they didn't happen on Earth-Σ, and that that's how to make the two Earths more distinct. But Earth-τ's history from 1986 to 1991 closely parallels Earth-Σ's history for the same span of time.
Rogue wears rouge.
Angel knows all the angles.