There's supposedly a lot of issues with Batman:AC and DX11. I find if I turn off Tessellation it runs nice and smooth, however in DX11 I do get the occasional CTD which can be a pain if the game hasn't been saved for a while.

well the good news is they released the update for the game and it dos fix the DX11 issues
http://store.steampowered.com/news/6939/
so0o far i have noticed with DX11 on the majority of objects load roughly half the time compared to with DX11 off (ex. character trophy's)
the only other oddity ive notice while playing with DX11 settings on, is when the game is loading, going threw all the logo intros, is when the nvidia intro plays the sound gets oddly choppy, where without DX11 stuff on its all clear, how it should be. its nothing big at all but hey just throwing it out there =P

still sucks tho took like 2 weeks for the update to be released being i beat the game already, but still have all the little stuff to go threw collecting along with the riddlers revenge area. Its a solid 20 hour game threw the story line and i was telling a friend that for anyone who was a fan of Prototype, with all the fluid free roam and making the player actually enjoy the side quests, is how BM AC brings that back =P

Through. Threw is throwing a ball. 😉
Sorry, it just stands out quite badly.

Anyway, I thought the DX11 stutter in the NV logo was related to Realtek chipset based audio cards, but I see you are running a XFi card - correct?
I get the same with my on-board sound.

Actually 2 weeks to release a patch is pretty good really. I too have finished the main story, and just about all the side quests. Mainly working on the riddler secret - you need to collect ALL 400 to enable the mission to arrest the riddler.

I'm interested to see if the patch also addresses to occasional CTD I experience...