When it comes to practicalities for mankind, I am not changing tone - it is very, very, very empty. Even in our own solar system, the distances of nothingness are humongous. Heck, I can grow an impressive beard just flying to the next planet, if I didn't kill myself for being bored witless.
We're not made for living on other planets, certainly not in our solar system. The gravity is all wrong, the day cycles are way off from what we're used to, the seasons are out of whack, as is a reliable moon, and the temperatures are extreme. Just looking at the horizon will disorient us. The lack of water is a problem, not to mention being able to grow anything or breathe anything without some serious artificial help. People seem not to realize how difficult it is to sustain life on a planet that has none. A trip to the Antarctic would be a walk in the park compared to this. Not to mention that the dire, un-Earthly circumstances would be devastating for the human physique and cause for serious health issues and premature death.
I'd prefer we clean up the one planet where we feel quite right, which is probably easier to accomplish than moving our civilization to a lifeless rock further up or down the solar system.