Summary: I am a professional photographer and use this card as my main compact flash card. It has a fast transfer speed and the reliability has been superb. This is my second card and I'm about to get my third. I think for the value, this is the best deal out there on compact flash.
Works Well with Nikon D700, but not much faster than the 266X
Dr. W. C. Wu, Amazon
1 May 2014
Summary: I believe the D700 camera body has a buffer, so that drives the read and write speed. This 600X "supposed" to be faster when you dump your files to the computer, but I found in my particular set up the 266x is maybe only 5% slower on doing those tasks.