"Poll question: Now that you have seen the performance difference between the the XQD memory card, and CF memory cards on your Nikon D4, which of the two have you set as your primary memory card in your D4?"
My tests have shown that the XQD (H series) memory card is about 27% faster than the Lexar Pro 1000X CF card, and 34% faster than Sandisk Extreme Pro CF Card when using 32GB cards and storing my images in RAW format. I've now set my D4 to use my XQD cards as my primary D4 memory cards.
Especially when photographing wildlife, such as birds, and therefore shooting in bursts of 10fps, the image storage speed of my memory card is very important. The current XQD cards far exceed the CF cards at this time. With the new series S, XQD cards about to be released for sale, which are 32% faster than the H series cards, the difference will be even greater.
Couple that with Lexar, finally about to release their XQD cards, which should drop prices, going with the XQD card over the CF card should become an easy decision.