I can add that I bought a 32G Extreme 60 for my P45+ and it didn't work, so I left it in my Canon where it works phenomenally well. Phase even sent me a beta firmware upgrade for the P45+ to try, and it didn't work with that either -- has something to do with the reader I assume. Anyway, I upgraded to the P65+ and it works fine in that back, and in fact the card I am using in it now. Only complaint is it takes about a full minute to format, and several seconds to "check" when you power up the back if you have the card check option set... I found the older Extreme III 16's to be bulletproof in my P45+, FWIW.