As mentioned above I plan to use the 32GB 400x (45MB/s I think) Sandisk card for "regular" shooting. I want one "fast" card for action shooting. I do not plan to use SD cards. I have a half dozen or so "slow" cards (133x) that I use with my D200 that will work with the D800 for "slow" shooting, so that is also a possibility. I do not need for all D800 cards to be "fast" cards. It is interesting to note that the Lexar 800x cards have a read speed of 45MB/s and the 600x Sandisk cards ("Extreme Pro") cards have a read speed of 90 MB/s. So I don't understand what the "speed ratings" (400x; 600x; 800x, etc.) mean, or if they mean anything. It appears that that number may be misleading. That is one reason I started this post...to share information and learn more about the ratings and relative values of these cards.