[Original Comment]:
I bought this at release.
Luckily, I was able to play the base game at launch without big problems.
Then I had to wait up to this very day, about four months, to get the dlc with the season pass I bought, which has been available for months on consoles.
And while it DOES say that I own the season pass, all I have in my inventory (ingame inventory as well), are the steam preorder skin pack and the New 52 Skin Pack.
What.
The.
Hell.
[Edit]:
I can't speak for everyone in general, but when I started Steam this morning, the game started updating. While the update is still in progress (about 8 gb btw), it seems the season pass works how it should now (meaning all DLC are now in my "owned dlc for this game" section for Arkham Knight).
At the moment, I'm not changing my recommendation though, because there are only the "yes" and "no" extremes. Also, I didn't yet play the dlc yet, because as I said, the update is still going.
Right now I'd advise to wait a little longer and see if it works for everyone now.
From my personal view, I wouldn't recommend it though. The price is insanely high and you would support a company that has done nothing to justify fan purchases in the last months for PC players and isn't even doing anything to make up for it now (gifting us all previous Arkham games is not making up for it to me, it's an insult / a derision).
I will update this review after playing the season pass content, and see if I change it to a thumbs up.
Highly doubt it at the moment though.