It's pretty much what you said, an older version of the same thing.
Morrowind has:
- Simpler, but far less frustrating combat.
-More restrictive fast travel.
-No "go to this exact spot shown on the map with a big red arrow to instantly complete quest, you drooling monkey" function
-More original, but also a lot more boring main quests.
-No enemies that level with you, which makes it an actual rpg, unlike vanilla oblivion, which might as well be strange little first person action game.
-Not as generic/stock as oblivion.
In the end, both games blow donkeys and you should probably play something that's actually fun, but if you want to play oblivion, I would suggest to mod the crap out of it. And don't try to store your shit in random barrels or crates, etc, because, for some reason completely alien to human logic on this planet, galaxy, universe and plane of existence, the containers will reset after a while and your items will be forfeit.
For mods, I'd recommend the oblivionXP plugin, which changes the tes leveling system to a classical xp based system.