I have 2 sdhc cards in my D600. They are class 10, each rated at 45mb/s. Viewing the image on the lcd screen seems to take about 2 seconds or so for the image to appear. I have not shot video yet, but it seems like this card may be too slow for that. The manual is not very clear other than to say use class 10 cards up to 32mb. Any one know what speed card would be best for this camera?