Arkham Knight was released yesterday on PC, and almost immediately users reported that the port was, to put it simply, terrible. Capped to 30 FPS and buggy to boot. Users also reported that you could uncap the frame lock with an edit to the config ini. However the game does not like running about 30 FPS, and would crash even more frequently after the change was made.
This isn't the first time an Arkham game has run terribly on PC. Arkham Origins had some massive issues on release, including one gameplay breaking bug that I encountered where you could not leave a room, forcing you to reload an earlier save. That port was made by Iron Galaxy Studios. Take a look at that list, and note the most recent entry. Sigh. I shouldn't be surprised, but I am. Rocksteady, who made the previous core Arkham games (including the PC ports), have generally released great products for PC gamers.
So as a PSA for anyone who reads this, don't buy Arkham Knight right now. If you did fall into the preorder trap, remember that Steam now has a refund option, and this is the exact sort of situation where using that option is the best course of action. Don't support publishers and devs who treat our platform like this. If they fix the game, then look at picking it up. I'll keep my eye on the situation as it develops.
EDIT 1: Apparently the port was developed by just 12 people from Iron Galaxy Studios.
EDIT 2: Further news points to the PC port almost being deliberately downgraded. An image showing the differences in rain textures between the PC port and the PS4 edition shows a crazy amount of difference. Rock Paper Shotgun also posted this video showing the PC version in all it's "glory".
I'm still showing restraint on the crazy theories about WB Games deliberately doing this. That said however, I doubt I'll be purchasing this game at all.
EDIT 3: There is a theory that Iron Galaxy Studios only had 8 weeks to port the game. It's only a theory, but could definitely explain where the issue started.
EDIT 4: Rocksteady have suspended future sales of the game on Steam, and made a post regarding the issues here.