One thing I did notice was that the buffer was clearing out 4-5 times faster with the 1066x over the 400x and when the shots started to slow, the 1066x was very consistent and slowed from about 4 frames to 2 frames a sec, in contrast, the 400x would slow to 1-1.5 and would hesitate sometimes

Clears a full buffer in about 5 seconds

It rapidly clears the buffer and here I am ready for the next series

No transfer errors, no write errors (probably the most important issue to me) and they are fast (I haven't been able to overrun the buffer yet, more than likely because of the card speed).

I get a few more shots in my bursts before the buffer fills up because the camera is able to clear the buffer to this card so quickly.

/s continuously while the camera trying to clean up its buffer.

Once I hit 40, it takes maybe a second to clear the buffer

With my old CF card it takes about 18 seconds to completely clear the buffer

I found that these Lexar CF cards allowed my camera to clear its internal image buffer faster and capture more images in a period of burst shooting than my previous CF cards that operated slower

I use it on my 5D Mark III and it improves continuous shooting buffer: I can take slightly more RAW shots before the camera slows down

I bought this 1066x card, the fastest CF card on the market (that I know of) and now the buffer clears so quickly that I don't worry about turning the camera off prematurely.

It clears the buffer quite quickly and allows me to keep shooting even after the buffer fills (at a slower, but doable rate).

On my 5d mark 3, I am able to clear the buffer about 3 times faster than my SD cards were doing