On Lore, I'm a fan of storyline. I've always felt that entering a dungeon or a raid without understanding what the hell I'm doing there was a big disconnect and ruined the motivation for me. I'm sure that if we were to test this, a lot of people would probably report that completing an encounter with a named, lore rich boss is more thrilling and prestigious than defeating an unknown. This also works from tier to tier. I can certainly understand people who hate it and just want to melt faces, all's fair in love, war and MMO's.
EDIT: I've dinged 59 this morning. 5 million XP to go. Just starting Ashora and then have the Infinite Steppes left to complete.