I’m glad to see that the Beerocracy (Beeruser and UncleBeer) are taking the question seriously. I’ve always liked the quote that I believe is attributed to Carl Sagan: “Either we’re the only intelligent life in the Universe. Or we’re not. Either way, it’s a sobering thought.”
A quick semantic quibble: UFO means “unidentified flying object” and is not synonymous with “flying saucer.” May I suggest ETV (extraterrestrial vehicle) when we want a quick and dirty term for “things observed which we want to describe as what aliens are flying”?
Given that, I think we could learn an immense amount from them, even if they are advanced beyond us only in having ETVs. In virtually every social-science field, we are handicapped by having only a single intelligent species to study. The religion issue is, as UncleBeer points out (and which has been dealt with on another thread) obvious. Biology, astrophysics, planetology, you name it: having their data would change our world.
Question: There is an assumption in much science fiction that the more intlligent or advanced race must exercise extreme care in dealing with the less, to avoid instilling a racial psychic inferiority complex. Do you think this is valid?