Ok I just looked up Kids N Motion. If it's the place in Woodbridge, that's way too far for a bday party. Expect lots of declines if you have it there.
Pump it Up Manassas is about a 25 minute drive from our home, as it Sportbounce (we're in in NW Vienna) and Sportbounce is NOT small. Are we talking about the same place? I do like that Pump it Up's party space it private and you get away from all of the action while you have cake/pizza. Sportbounce doesn't offer that option.