This is because Trinity Blood is in fact quite dry and boring for what it is about. Normally a plot like that would be played with much intense politics or more like Ghost in the Shell but instead they made it all philosophical and shit which makes a dry setting even more dry. Needless to say it really is slow for being hyped the way it is I remember the previews made it seem like a story about a badass Cyborg but in fact I notice it focuses on a character by the name of Father Nightrode or something like that can't remember.
The only appeal this had to me was the mythical creatures beyond that it is a pretty poorly executed anime. Almost forgot to add that the mythical creatures are portrayed quite accuratley to written myth.