@Yuugi's:
Long-running series like One Piece are simply weekly filler and commercials for the lowest common denominator. The quantity of episodes that need to be made make it unfeasible to maintain the quality of a late-night anime, unless you have the luck of allowing for your production to finish over a dozen episodes before starting broadcast. Late-night anime are for Otaku, who have higher production standards and typically follow shorter series in general. Since most studios only produce two or three series a year producers don't have to squabble over their regular talent contacts and can pour more of their efforts into a single series, as well.
Tiger Mask W is a rare case where a Toei Animation producer (Gyarmath Bogdan) was seemingly able to not only begin his series with not only a healthy lead time, but also recruit numerous good animators and directors to continually work on the series. The Kamatani Haruka storyboarded episodes are the series' best, especially when she is teamed up with Watanabe Koudai as her animation supervisor.
Kagawa is the one who credited by his fellows in the studio for putting his weight there and pulling these talents, also haveing his old Senpai Hayama helped perhaps in attracting more talents