Heidegger's Interpretation of Kant: Categories, Imagination and Temporality

Is there any justification for Heidegger's famous 'violence' against Kant's philosophy? An independent assessment of the worth of Heidegger's argument is also made all the more pertinent by the evident misgivings Heidegger had about his interpretation of Kant. We must ask of Heidegger's interpretation of Kant: 1) Is this good Kant? and 2) Is this good Heidegger?