Lexar 1000 vs XQD
I have both and in the real world of shooting long bursts at 10fps, frankly I can't tell the difference in the camera.
The difference comes in when I go to download from the card to my computer. I have USB 3 readers for both, yet the Lexar 1000x downloads faster to my desktop computer.
It is a different story when I download to my laptop. I have ExpressCard readers for both XQD and CF cards. The XQD on the ExpressCard reader downloads faster than on the USB 3.0 reader. The Lexar 1000x won't even read on the Lexar ExpressCard reader (Lexar knows about the issue and says the ExpressCard reader has a max speed of 800x). The Lexar does read on the USB 3.0 reader.
So in summary, right now it is a toss up in my opinion as to which is "faster". The only advantage the Lexar 1000x clearly has is that I can also use it in my D800, D3S and D300 cameras, while the XQD can only be used in my D4 camera.
Clifford W Martin