A few things I've really taken notice of just with my character just in a few hours (and NPC's of course):
she breathes,
there's proper head tracking,
she has facial expressions,
she blinks,
I can jump properly, and more that I can't think of right now.
The game is rock solid stable with a lot of heavy mods. No annoying stutters and no need to use half a dozen 3rd party utilities to overcome the other problems.
My load order, which will grow, if anyone's interested. I'm using Maskar's Overhaul which I like a lot. It's hard but configurable via it's ini or on installing. I'm using WAC as well.
Active Mod Files:
spoiler:
This is Maskar's Oblivion Overhaul. I used to love OOO but this, I think has taken top position. For me anyway. That's not taking anything away from WAC because it does different things.
And this which makes the default races actually look decent. I was amazed to say the least when I saw it in game.
Oblivion Character Overhaul by Nuska who does great work.
Also I really like this - Combat Stance Reanimation.
Now for some screenshots. I will write a little back story later, but my character's name is Eliza Thorn and she's a warrior mage. Using Deathknowz excellent DKImperials. I did add different hair though, Eliza's style isn't in the mod by default.
Oh, and I know there are jaggies. I've been deciding on whether I like HDR or Bloom and with AA on I can't use the default system to take shots. I don't really want to use an external program like FRAPS unless I have to, but then I don't care that much as my main focus is playing the game, not screenshooting.