I pre-ordered this on Steam a couple of days before launch. As of right now, it is sat on 1h50m playtime and I'm not touching it again until either we have news on when a major patch is expected or we start to get close to two weeks after release.
Because of Steam's new refund policy. If you have less than 2 hours playtime on a game and it is less than 2 weeks since release (or less than 2 weeks since your purchase, if you purchased it post-release), you are eligible for a refund. The game in its current state is a very sorry sight indeed.
My personal experiences with it haven't been as bad as some. I have an i7 3820 @ 3.66ghz, an Nvidia 980 and 16gb of nice fast RAM. I also, crucially, have a 500gb SSD that I use for my OS and for drive speed sensitive games (as well as some big old traditional drives for everything else). Running from the SSD and with an .ini tweak to remove the 30fps cap (yes, a 30fps cap in a PC game in this day and age), I can manage a not-terrible level of performance. Framerates with all settings maxed in 1080p flicker between 35 fps and 70 fps, depending on what's happening on screen, though the wide variations do produce some ugly artefacts.
When I first installed the game to one of my traditional drives, performance was appalling. While framerates when stood still doing nothing were the same, taking almost any action in-game, from moving around to entering a vehicle or changing areas, would produce large framerate drops, hideous stuttering, broken textures and texture pop-in. This game has some serious issues with data streaming from storage drives.
The game is also ugly to look at. Ok, ok, I'm being a bit harsh there. As a bare-bones PC port of a late-cycle 360 or PS3 game, it would have looked ok. But compared with PC versions of recent efforts like Shadows of Mordor, Grand Theft Auto 5 and The Witcher 3, this looks terrible. Bear in mind that all of the above run at higher and steadier framerates with all settings maxed on my PC. In Arkham Knight, NPCs movements are repetitive and robotic, textures are low-resolution (the game will only allow "low" or "medium" detail textures to be selected, implying higher detail textures were removed at the last moment) and basic visual effects from the console versions are missing.
My experiences put me at the better end of the scale. I have a powerful PC with a single-Nvidia-GPU setup. Weaker PCs, or even more powerful PCs with multi-GPU setups or AMD cards seem to have things much worse. I've only experienced one crash to desktop - but that's as many crashes in under 2 hours of play as I've experienced in almost 30 hours of play in The Witcher 3.
A few wider points about this; while this game is particularly brutal in terms of its drive speed requirements, it is part of a broader picture that drive speed is starting to matter as much as CPU and GPU speed for PC gamers in terms of actual in-game performance (rather than just load-times). Watch_Dogs, Far Cry 4 and Dragon Age: Inquisition all suffered from in-game stuttering issues when running from a traditional drive - though not to anything like the same extent as Arkham Knight. An SSD large enough for games as well as the OS is becoming non-optional for serious PC gamers.
Second, this is the first real stress-test of Steam's refund system. To their credit, Valve seem to be honouring Arkham Knight refund requests without any qualms. And it's surely no coincidence that the first "broken" PC port to go out after the refund system was introduced has led to such a dramatic reaction by the publisher.