Since I bought D800e I got 2 Topram 600x 64gb and 2 Transcend 400x 32gb plus Lexar USB 3.0 reader. No problems at all. Getting almost full reading speed from these cards. The 400x Transcend seems very close to 500x actually. I also bought 32GB Topram 600x cards but they did not work at all in D800e even though they worked perfectly in all my other cameras. Very strange. Anyway, I already have 16K images from D800e and about 12K from 7D without a single glitch. Total cost for all of these cards $300 which is a lot less than most other brands.