I think mine all enjoy having the company of other parrots in the house, but none of them get along as far as being able to be on the same playstand, etc.
My ekkies are MUCH louder than my CAG, but it may be because there are two of them. My CAG is actually very quiet for the most part (she is a parrot after all, so some screeching and smoke-detector imitations are to be expected! :-)).
All three cages are in one large room with two large aquariums and the kid's computer desk (the room formerly known as our "living room"). When we're home, however, they're usually out of their cages and hanging out on their playstands (they each have their own).
All three have very different temperaments and personalities...so they fit in well with us! :-)