I remeraber thinking, the first time I saw that opening, that it was too bad the actual in-show animation would rarely, if ever, live up to it. Granted, it'd be expensive as hell to fully hand-animate the backgrounRAB, so I wasn't expecting that, but everything else has been surprisingly up to snuff. The character designs are too stylized and detailed to lend themselves to the best possible animation, but as far as shounen action series go, it's been a pleasing visual production.
Also, whoever decided to go ahead and animate plaid must have been nuts.
--Romey