Let me put it to you this way:
I got more enjoyment out of this expansion than I did with ANY of the New Vegas DLCs. They made quite a few blaring mistakes, but what they did correctly, they excelled at.
Like I said, I'll be watching DLCS, and as I'm doing currently, roaming the spoiler forum.

Some things are better seen or experienced rather than just explained. I think if I see Youtube vids of it, I'll be able to tell if it's for me or not. Again, I'm not meaning to sound like "Dawnguard sounds like complete crap," but it just sounds like it's going in a different direction than the direction I prefer (I prefer story, character diversity and replay value, Dawnguard seems basic on story and low on character diversity). If I'm wrong, I'll know when I watch a let's play.
I mean as a short summary, I feel like most people would be relieved to hear they can support the Dawnguard and be a Vampire Lord at the same time. I however am not. More power to those that do, but that's not my kind of game, personally.