Awesome, Dear Boy: The Spanish dub director, Alfredo Martínez, watched Manga/X1999 entire and studied the work of its voice actors in order to make the Tsubasa dub more faithful in the common characters.
The Spanish dubs of the movie and the anime were done by completely different casts due to basically a dynastic war of distribution companies. It started when distributor Jonu Media chose to dub the Cardcaptor Sakura movie with their own VAs instead the ones which had voiced the anime, Arait Multimedia's voicecast, which caused a great offense to both Arait and the fandom. In response, after Jonu dubbed the Tsubasa movie and in turn lost the rights of the anime to Arait, the latter refused to use none of Jonu's voice actors and instead used their own, which also was the original cast from Sakura. The return of the voices was liked better by the fans, but the subsequent heat with Jonu pretty much rendered the OVAs impossible to be distributed in Spain.
CLAMP originally made the storyboard for the second season opening. But it got rejected by Bee Train in place for the current second opening which is a slide show.
The anime could have a third season. But due to NHK's Executive Meddling to make a show lighter and kid-friendlier as opposed to being close to the manga which is heading toward Darker and Edgier, CLAMP became disappointed with the results and had Production I.G continue the anime in a form of the OVAs.