Maturity then: 10-year old kid just starting out with a dream. Childish, impatient, impulsive.
Now: Still prone to impulsive behavior, but he thinks things out much more than he used to.
Int. then: Extremely limited. More often than not used Pokemon with a type disadvantage, and always seemed to be getting advice.
Now: He can pretty much do things himself, training and battling mostly on his own, and coming up with strategies on the fly when he needs to.