Summary: The Good: 30 hours of game play, tons and tons of new content, better story, great new quests, new art style is wonderful The Bad: After you finish everything you'll want more, feels too much like Oblivion The answer is yes plus some!
Summary: As an extension to Oblivion content, Shivering Isles is excellent. Clearly, Bethesda programmed it instead of farming it out to some other company to work on. If you like Oblivion and want to play on, get Shivering Isles. Maybe it will help you make it to 11/11/11, the release date for Skyrim.
Summary: The graphics, gameplay, and map size were perfect, making for an excellent play. Just as when you first play Oblivion and it is as if there is a vast expanse of world to explore, Shivering Isles is much the same.
Summary: If you even so much as subtly enjoy Oblivion you need to power on through to the shivering isles. It offers an array of new questlines and interesting characters. If your looking to bank achievements be sure to save before you become the duke of either mania or dementia. Great Purchase!
Summary: The Elder Scrolls IV Oblivion is my favorite game, and The Shivering Isles add-on is a must have to add additional quests and content. I would highly recommend this add-on for game enthusiasts. Another great add-on for this game is Knights of the Nine.
Summary: The Shivering Isles creates a new world for you to explore, with new monsters, new ingredients to try out at alchemy, a schizophrenic world to explore, and as part of the storyline you'll get a cool two-in-one sword, the Dawnfang/Duskfang.
Summary: This expansion is pretty fun. Who doesn't like to run around in a world where insanity reigns supreme? The only draw backs is that it doesn't add many new things. Oh, it does add so much. New characters to interact with.
Summary: As I have not yet played Shivering Isles, I look forward into venturing into it soon. But I do not always like to rush in to playing a game right when I get it instead I like to wait a little while and play its other half Oblivion gather the controls and refresh myself before playing.