Just had our first 7 months ago. My wife, he, and I flew to spend time with family for a couple of weeks and I do have to say that he really has flourished with all of his cousins and other family around. He is much more vocal, seems to be more mobile, eating a bit better, etc.
I think he was getting bored or having limited stimulus staying at home with my wife and I and occasional grandparent visits. We are thinking of some daycare once we get back home to keep the the action and engagement up until he gets a sibling.