Yes, from about 400 (Edit: it's 256) move speed (the calculated movement speed, not the Speed attribute) it begins to peter out, reaching half amplitude at double that speed and then asymptotically approaching zero the faster you move.
As a result of the above, this isn't random, it ends up being more of a visual vibration, no worse than what your weapon hand will already be doing at those speeds, and less extreme than switching to third person where the animation itself moves the camera left and right at a fixed rate.
What I will do though is make the peak amplitude speed configurable, so if 400 is still too much (or not enough) everyone can adjust it themselves to whatever value they want.