I just ran it again three times with all settings turned off and just the body cap on the camera shooting RAW - 23 frames on the 1000x Lexar, 35 frames on the 1067x Sandisk. This is the number of frames on the 5DIII before it begins slowing from the max frame rate. Yes, you can keep shooting at a reduced frame rate and eventually it will slow even further, but I'm measuring (and interested in) the number of shots at full frame rate.
Also, given these results, I can confirm that aberration correction, vignetting removal, and standard levels of high ISO noise reduction don't impact frame rate.
mack..I didn't leave the body cap on, I shot at a a fixed subject - large RAW - I'll also try it again and check back. do you have image quality set at "10"
edit...I wonder if this is the reason for the diff....from Adorama website:
Lexar Pro 1000x 16GB UDMA 7 CF Specifications
Read Speed 1000x (150MB/s)
Write Speed Max 966x (145MB/s)
Compatibility UDMA CF and CF devices
this would mean that there are two different lexar 1000x cards, both at 150 read, but with 95 and 145 write.http://www.adorama.com/ILXPCF1K16.html