I like it simply because it's..... PROGRESSION.
Do Raid A first..... then go into Raid B.
This just takes me back to the old BC model in a way though. Heroics are going to get old in some way because.... guess what.... they're the same bosses those players have already beaten. I kind of hate to say it, but I'm beginning to agree with the old school crowd in a way in that, "valor points" might have "ruined the game".