In the view tab (novice mode unchecked) whats the difference between linear/quadratic acceleration?

Linear acceleration will adjust the rate at which the view distance changes at a gradually increasing amount, but when changing the view distance by a large factor it tends to not settle down before another adjustment is needed - it's best used when little adjustments to the view distance are needed, i.e. your overall framerate is fairly stable to begin with.

Quadratic acceleration will allow for more sharp changes over larger view distances - it's more responsive and smoother overall imo than linear acceleration; it's better used when framerate is less stable and there's a tendency for FPSO to want to adjust the view distance often.