So far the response seems to be extremely positive, with many saying it is on par with Shivering Isles, although both packs have got their own strengths and faults. Shivering Isles was fairly large, but it didn't add much in terms of weapons/armor/equipment crap and just like in Oblivion, many locations lacked features that could make them stand out. Dragonborn adds a smaller landmass, has got an underdeveloped antagonist, and a short main atoryline (shorter than Dawnguard), but its side-quests are supposedly fantastic, it is challenging, it's got some fantastic minor characters (some of which also appeared in Morrowind), it adds large amounts of lore on subjects that previously left us in the dark, and has got better dungeon design.
My biggest complaint with Dragonborn is that it currently isn't available for the PC.
