I'm expecting my first child in April, and am trying to decide what stroller(s) to get. I really like the Baby Jogger Summit X3 because it is so easy to fold (one hand), and I can use it as a regular stroller, with a carseat travel system, and later, as a jogger. Does anyone have any experience with this or other joggers? I'm also wondering how long I have to wait to start jogging with baby? Will it be winter time before he's old enough?