As it was mentioned gaining experince and basic skills take time regular tournament can help here, but rules changes the encounter. I'd enroll in a full contact school that stressed that kind of sparring if I wanted to do full contact sparring. Your skills and technique will be adjusted for that type training and competition.
So no you don't learn more outside the dojo rather then in the dojo, until you learn something while training inside the dojo. Sparring unfamilar systems and methods outside or inside the dojo helps gain further expereince. But its safer inside the dojo where some kind control is mandatory.
Sparring outside the dojo is a risk and should only happen when you have confidence in your partners and all know what level you all want to train at. Getting knocked out by superior fighters early in your training isn't going to teach you anything, except make you punch/fight shy!!! Go slow and learn well that will help/save you, this is done inside a dojo under a good Sensei 1st.
Just my 2 cent.