Part 2 is more epic and on a grander scale. as a result we got explosive jutsus and alot of hax. plus alot more people die IMO.
part 1 was about showing how the kids and some jounins fought and was more about taijutsu and smarts.
i like both.
part 1 naruto had battles that actually involved thinking and stragety
nah i think part 2 has as much strategy as part 1. shikamaru and kakashi vs hidan and kakuzu, jiraiya vs pain (the reason jiraiya lost is because he didnt know about pains abilities), sasori vs sakura and chiyo, most of sasukes fights (even though sasuke vs danzo was a spam fest, it came down to battle smarts in the end and sasuke's was better). naruto vs third raikage.
plus part 2s fights are more emotional and meaningful. when the "bad" guy loses, you still feel for him. i didnt care about any part 1 villains except zabuza and haku. and the good guys actually lose and have to retreat in many part 2 missions.