As an addendum to the high framerate section...
It is worth stating that when using a mouse, the smoothing and/or mouse acceleration are in some way affected by your FPS. This is fine up until you experience significant frame drops (usually sub-30), at which point controlling the camera is like trying to control a drunken ice skater. Given these drops tend to be inconsistent besides their relation to high fidelity areas, this can lead to the same mouse input having wildly differing amounts of camera movement completely out of the blue.
For some reason, this does *not* affect controllers, and control remains tight with an analogue stick even at low FPS. This is likely related to the team being encouraged to focus on controllers as the main control scheme despite the benefits of a mouse and keyboard setup.
The best way to mitigate this issue I and others have found (besides using a controller) has been to edit secretsettings.txt and lower the physics calculation rate and to adjust graphics settings until frame drops are less common. The physics trickrate has the biggest impact overall.