If it helps anyone, I was suffering the same input delay issue.
After trying many things and settings, I found a fix that makes the game actually fun play: use windowed mode instead of fullscreen (resolution don't matter).
Hope that helps.
Unfortunately, this does not help. My specs are below.
-Windows 7 x64 SP1
-Intel Core i7 2630qm @ 2.0GHz
-8.00 GB RAM
-nVidia GeForce GTX 460M @ 1535MB RAM
In both moving and attacking there is a noticeable delay of slightly less than .25 secs, making it possible to attack while moving backward because the game doesn't seem to register the input in a timely fashion. Related to this is the issue of dead enemies still doing contact damage, viz. if a player jumps and attacks at the same time, then connects with the enemy and kills the enemy, the player will take damage from the enemy if they are close enough for the jump to allow them to make contact with the dead enemy before it disappears.
The first issue can speak to an issue with the input device, something that is minimal enough to only be noticed by people that are paying close attention. Alternatively, there can be something in the code for the PC version of the game that links the first issue to the second issue, where the game doesn't recognise the change in state, for a lack of a better word, in a timely fashion.
The game isn't unplayable -this is more along the lines of a game error/bad mechanic that the player simply has to work with and can work with- but the game is definitely hamstrung by this set of issues. Addendum
After doing some quick Google searches it seems that the delay is relegated to the PC version of the game and also affects players using a gamepad, whether official XBox controller of not and wired or wireless or not. At this point it seems to me that, much like with Dark Souls and Dark Souls II, the delay is firmly a software-side issue that can but will not necessarily
be affected by the integrity of the input device. Addendum #2
Changing to Windowed Mode itself was not enough to mitigate the input lag, but lowering the resolution and changing to Windowed Mode did much to mitigate it. Instead of playing in native 1920x1080 I am playing in 1600x900. Issues with the character attacking in the opposite direction as described above still occur with frustrating regularity, however much of the input lag is gone. That this bit remains means that I either need to play with an even lower resolution (which is just...well, fucked) or there is a more meaningful issue with the code that doesn't allow for a workaround.