The gold chuchu's sprite isn't bad, but it deviates from the original look in The Wind Waker and it also doesn't fit the Minish Cap's style or perspective. It could work very well in a game with a different graphic style, but the original sprites in The Minish Cap really couldn't be any better. The gold chuchu's sprite looks a bit Castlevania-ish actually, except for the fact that it's front-view.
(But I still think the Minish Cap sprite looks better, regardless of style.)