Dawnguard was amazing for me. After being out of the game for 5 entire months I really was doubtful that a dlc with only about 500 something mb would be enough to satisfy me for even a day. The storyline was great, but even more important to me was the introduction of new places to explore and new enemies. I loved how Serana played a role in all my adventures and how she actually felt like a real companion and not some robot. Not to forget the fact that the new weapons are awesome. New side quests added were great, the Lost to the Ages quest was one of the most fun I've ever played. So far I have only completed the Dawnguard side of the dlc and I spent already another 24ish hours on just that (no I'm not slow my level 60 breton destroys everything in sight even on master difficulty). I'm glad this dlc came out and I think Bethesda did an amazing job on it.