The figures put up by Kodak suggest blooming protection is 1000x. I've seen a slight effect in preview mode (i.e 4x4 binning) on mine with a 8" f5 and a few seconds exposure on a bright star. But obviously I need a larger scope
As some of pointed out this is a great sensor for shorter focal length optics. It also has some other nice features like the angle response, i.e the microlens remain effective for steep light cones. So the loss of sensitivity is small even for f2 optics. If you look up the Kodak datasheet for the 8300, look at the "KAF-8300 Angle Response - White Light" chart. I've attached a copy.
Christian Buil recently did an interesting comparision between the KAF-3200 and 8300 here:
http://astrosurf.com/buil/qsi/comparison.htm
Terry