I’d say you can get very close to the same gaming experience.
I still miss the customizable interface from Morrowind, the text based storytelling (a lot richer than voice acting) and levitation also to some extend (I know there is a mod for that but I got used to not having it by now) but that’s about it.
First, some features in Oblivion are real improvements on Morrowind:
– better graphics (from spell effects to lush environments)
– more realistic NPCs (Radiant AI is not perfect but it is an improvement over static NPCs from Morrowind)
– physics effects (makes the world more tangible even if it is not perfect as well)
– mounts (although lacking the capability to fight from a horse)
The mods I currently have eliminated all of the things I found annoying with Oblivion :
- fast travel (disabled by Cyrodiil Transportation Network)
- world wide leveling with you (replaced by static levels in OOO)
- game console interface (replaced by more immersive interface mods and wz interface)
- cryptic persuasion system (simplified by a persuasion overhaul mod)
- missing travel agents : land travels, boats, mage guild teleport, mark/recall (replaced by Cyrodiil Transportation Network)
- bland map (replaced by aged, color map)
- missing levitation (available in Supreme Magicka)
- clumsy tutorial (replaced by simple questions on a ship to Anvil in A new beginning)
- static prices and unlimited vendor gold amount (both fixed by Living Economy)
- repetitive scenery (the Unique Landscape project brings more diversity to Cyrodiil)
And you also have the equivalent to some of the best Morrowind mods :
- gold weight and better encumbrance mods
- eat, sleep and drink mods (fixed by mods such as Hunger, Thirst, Sleep)
- texture replacement (Qarl’s is almost a standard)
- better bodies (TNR is astounding)
- illuminated windows
- more immersive sounds (Atmospheric Oblivion).
Finally, some mods bring back content from Morrowind into the Cyrodiil province directly :
- Books
- Unique armors and weapons (Old School Artifacts)
- Creeper
- Guars (wild Guars exist in MMM and pack guars are now included in Tamriel Travellers)
- Dwemer spiders (included in MMM)
Unfortunately, many features were unique to Morrowind and cannot be replicated as demonstrated in this Bethesda forum thread.