Just want to draw attention to perhaps the reason why full sized expansion packs are unanimously (thus far) considered superior to F3 sized packs.
When you develop an expansion that is large-scale you give yourself more room to be creative and a more suitable space to pour content into. The story line for any of Oblivion or Morrowind's expansions had far more gravity and importance than any of F3's DLC (with the possible exception of Broken Steel). There's more room for minor, small additions like smaller quests and NPC's.
If it's a bigger addition then there is simply more room for significant content, and it makes the content feel less like an "addition to" and more like an "extension of" the game. It creates a more memorable experience for the player, and a area that actually adds to the players proverbial playground or sandbox.
Consider this; upon finishing any of Fallout 3's DLC the player never returns to those environments. They merely pick up their loot and leave, bringing with them only the memory of the mission and the goodies collected. A Morrowind or Oblivion sized expansion provides a new world and populace for the player to visit continually, an extension of the world that provides cities worth returning too, and reasons to come back.
100% agreed, I couldn't say it better. I just remember how much fun I had in Tribunal and Bloodmoon. Tribunal offered a completely different experience that complemented oh so well Morrowind's main quest. A big, unique city with a vast system of undergrounds sewers, caverns, tombs and such. Oh, and the artifacts museum! And Bloodmoon with snow and trying to make the Imperial settlement get on its feet, werewolf attacks and such. If anyone could ever get tired of Morrowind, that was the cure. Shivering Isles was great, but I still think it fell a bit short compared to these two. Hell, Bloodmoon brought Lycanthropy among others, new factions and such. How can you prefer DLC that limits creativity?
And I can't understand how it wouldn't work even if it's not the industry standard. If most are willing to jump on the first DLC coming out, I bet they'd still be willing to jump on a full-fledged expansion to a game they all love. I mean, people have been begging for a new ES game, why wouldn't a lot of people welcome with open arms and all new adventure? As far as I know, Shivering Isles fared pretty well.