Oblivion is like reading a comic book. M&B is like being given paper and pencil and told to draw yourr own. Way too different to compare. However, I'm a fan of exploring so Oblivion wins by far.
Actually, Oblivion is like reading a summarized album concerning several (around 4-8, IIRC) cultures, architectural styles, mythologies, religious beliefs etc.
Step 1: Uninstall Mount&Blade version .960 from wherever it is installed.
Step 2: Install Mount&Blade version 1.003 wherever you want, whether it's the same directory as the one the previous version occupied or some place else, it doesn't matter.