For me its definitely the "mount" and "blade" thing. I tried playing some older good RPGs again (Gothic, Morrowind, Bloodlines and the like) but it was impossible to bear the bad combat system/fighting mechanics. There is no game that I know of which comes even close to MBW in this aspect. Beating enemies and having a good fight was never so awesome.
brian0351 说:
This is the game I've been waiting for since Defender of the Crown!

Yes! This one was very cool. I still love the music and have it in my head sometimes. Did you manage to win jousting fights or rescue a lady? this was so hard.
I never did compare it to mount&blade, though. Would rather compare this part of the game to Pirates because of the freedom to move around, the big map and the adventurer feeling.
EDIT: Re-reading your post again I think this may be simply another aspect of the game.