It's a fair question. Certainly, Superman had far more famous and well-regarded runs than the stint from 1987 to 1993 that I intend to cover, and yet this run had several special things about it that have kept it on my radar for a long time now:
1. I grew up on the later Jurgens and Ordway stories in this run and remember them warmly, even if the early Byrne stuff is going to be a tad harder to wade through.
2. As the lead feature in the post-Crisis DC reboot, this might be the most meticulous continuity ever charted for a Big 2 superhero, and I think that's worth exploring. It also helps that so few creative teams were in the kitchen, stirring the pot, for the first six years of this reboot. I've stopped at 1993 because my own personal recollection suggests that continuity and creative control began to fall apart after that, but perhaps I am mistaken. Still, seven years of dense continuity across three to four titles per month (sometimes more, depending upon mini series and bi-weekly publication schedules) is darn impressive, especially considering the continuity nightmare that the post-Crisis Batman franchise became in contrast.
3. Along a similar vein, the post-Crisis Superman continuity is a guide-post to the entire post-Crisis DCU. Most characters weave through at some point or another, and when Action Comics goes weekly, it will be a major cornerstone of the post-Crisis DCU. Having grown up on the post-Crisis DCU, I'd like a greater understanding of where it all came from; how characters were introduced and first intermingled, etc.
4. Even more than that, I think I'm looking for the energy and enthusiasm of the early post-Crisis DCU that pervaded the pages of the Superman titles -- a whole comic book universe was being consciously created for the FIRST time in comics (even the Marvel Universe of the 1960s was an afterthought in the wake of the FF and Spider-man, and it was on a much smaller scale). And, while many comic book universes have been created and recreated since, few had the non-cynical enthusiasm of DC at the time -- truly believing they were creating a universe of iconic heroes that would last until the end of time, not just until readership numbers began to dip again.
5. This is really the last hurrah for Superman on some levels. In two more years, he'd become eclipsed by the success of the 1989 Batman film and the endless momentum of affection for the character that continued after, no longer the #1 Superhero in comic books. These were Supe's last years in the central spotlight, and DC really rolled out the red carpet for him in a way that the character will probably never see again.
Agree or disagree with any of those points (and I reserve the right to completely reverse my own opinions after reading these), but that's what's drawing me to this series.
Articles of interest in this thread:
-Highlights from the run
-A list of Superman's Post-Crisis powers/abilities
-The Post-Crisis Superman timeline