With the purchase of D4S and now the D500, getting the fast XQD card looks desirable/ tempting. Earlier, the XQD cards were prohibitively priced, taking them beyond my reach. Now Sony launched a new version, the M series with 440 X read and 180X write speed. I am planning to pick up a card or two along with the reader. Has anyone used the XQD? Your experiences and suggestions? I find the poor r/w speed of SD card a limiting factor for D500. 4K Video positively benefits from fast XQD. But even with the cheap new version, it is a lot of money. Any review wound be appreciated.