Season 1 Bosses, and Season 1 titans are almost all defense debuff, and attack all special skills.
Season 2 Bosses, Season 2 titans, and Rare titans, it can be better to go with HP.
Really depends on situation.
I would love to try creative emblem paths, especially with the current implementation of costumes.
([Suggestion] Same hero, free, class node reconfigure or some fun with class nodes)