Man, highschool was hard, you guys.
Did that make you feel powerful? Maybe now Jess will respect you.
To actually answer your question, though, 02 only had 12 episodes, and the last six or so were very, very rushed. Kanon '06 had twice as many, and as a result was much better paced - a solid budget didn't hurt things either.
But for christ's sakes, talk like an adult, not like a 12 yr old doing a Stewie impression.