Agreed on the interior. It doesn't do the theme justice...it seems lazy. Some good ideas that were poorly executed, with some other not-so-good ideas.
As for the exterior, I am a fan of the larger than life simple geometric shapes. The pavilion doesn't have the "wow" effect that Horizons used to have, or that The Land has, when I walk through the Innoventions breezeways from the central plaza to the East and West sides of the park. I personally would have liked to have seen one of two very different approaches.
1. Instead of the model planets and spaceship on the exterior, it would have been really neat if the exterior was much cleaner, with a large spire extending from the ground into the sky a couple stories. That way, SSE and M:S would have similar appearances to the Trylon and Perisphere from the 39 World's Fair, but with their sizes reversed.
2. Alternatively, if we want to go with a model of the spacecraft, build a forced perspective full spacecraft, booster, and launch pad/tower on top of the building. That way you feel as you walk into the training center that the real ship is off in the distance, poised and ready to launch on a nearby launchpad. Heck, they could do a "launch" every hour, with lights, sound effects, and visuals.
Obviously, to each their own. I like to think the aesthetics aren't just nostalgia for me. EPCOT has amazing architecture, regardless of what is inside the building. SSE is one of the coolest structures I've ever seen. I don't think M:S fits that architecture. It looks more like something you would find in DHS or MK. I realize that many of the buildings have "boxes" behind them...pretty much all except SSE, UoE, Test Track, and The Living Seas. But the architecture of the rest (all of World Showcase, and the rest of Future World) makes it feel like the buildings I walk into are full buildings, not just facades like M:S.
