I think the main problems with Skyrim were the inconsistent writing and quest variety, the DLC doesn't really do much to improve those situations unfortunately. I wasn't exactly in love with the combat system either but at least it was a step up from Oblivion. Base game already has a ton of repetitive content, I don't really want DLC packs filled with those. I'd really like to see better themed expansions for the factions with unique quests.
There are some fan mods that add some interesting quests but they lack the production values in official content. Still hoping for a proper Shivering Isles style expansion pack, Dawnguard is far from that. In hindsight I should have listened to the reviews and waited but oh well, I've spent money in worse ways. To anyone on the fence though I'd definitely say wait for a sale.