Your author reviews and uses many brands of cameras; some camera use CompactFlash and some use SDXC and some have dual slots, one of each kind. For the latest cameras producing big files, a fast SDXC card can make a noticeable difference in responsiveness, assuming the camera supports the latest protocols (older cameras not likely to benefit).
Card tested here: Lexar 2000X 64GB SDXC card about $99 with included card reader.
But the speed can very by camera (faster may not be any faster than a slower card in some cameras), and card speed can vary with card reader too.
MPG previously tested the Lexar 2000X 64GB SDXC card and found it to be blazingly fast with the Lexar-supplied card reader. But what about the card reader?