Not much to explore, at least not without going out of bounds for guests
On the theater side, you basically stand in a long hallway area for a while, then you go into the very large pre-show area and watch a "making of" video (that area is big enough to be its own theater), and then you go into the theater itself Although there is some decoration to the theater to match EO, it's all rather nondescript.
I never saw Captain EO on its initial run...saw it twice when it came back...once only because I never saw it and was killing time before heading home, had a Fastpass, and needed to sit for a while (wasn't feeling well...at a party over at Universal, I ate something that turned out to have strawberries in it, which I'm allergic too...fortunately realized it before ingesting too much). THe second time was ONLY because the family hadn't seen it yet.
It was, frankly, horrible. And I grew up on 80s music and MTV. The quality of the video was poor, the special effects was poor...the asteroid looked like a rock from someone's back yard. If George Lucas was ashamed of the Star Wars Holiday Special, which he had little to do with, I can't imagine he hasn't disowned this...
I think closing Captain EO would actually be an improvement, because it at least brings the hope that something else might happen...