I used to work in the HDD industry, and am very familiar with the seek algorithms used. Sorry, but your description of the move algorithm is completely wrong. Modern control implementations collect information about the actual output of the system (such as position) relative to the desired output (the target position) and act on it in real-time.
Modern HDDs (as in, anytime in the last 15+ years) have 'servo tracks' written on the disk. These are radial spokes of distance information encoded on the disk. Today's drives may have as many as 500 or 1000 of these servo spokes. The head is able to read these as it seeks across the disk, so it knows where it is during the seek. There is no 'stopping, checking where you are and making an adjustment.' It's more along the lines of 'checking your position as you move, and adjusting the voice coil voltage to give the optimum velocity and acceleration to land in the right spot as quickly as possible.'
There is an enormous amount of effort that goes into reducing the amount of vibration generated by the drives themselves, as well as minimizing the drives' sensitivity to external vibrations. However, there are specs for what the drives are able to handle, worst-case. By reducing the amount of vibrations they are subjected to, they will naturally perform better.
Being Slashdot, we need a car analogy, right? Cars are made to deal with headwinds and still get acceptable gas mileage, but removing the headwind will increase a car's gas mileage.