I was actually trying to test out my CF cards yesterday. On my Transcend 64GB 1000x card, on the May 17th build I couldn't get past 78.1 MBs so I got dropped frames at 1920x1080. I went back to the original May12th build and I could again record 1920x1080 at 81 MBs with no dropped frames.
However a funny thing happened. After looking at my video files, I found out that I was recording BOTH H.264 internal and RAW to the CF card. I guess with the May 12th build, you have to go into the menu to start recording. I must have forgotten that the start/stop button didn't start RAW, but I hit it and the H.264 started. My H.264 clip is actually something like 5min long, but I started and stopped RAW recording from within the menu. So I have exact matching video files of H.264 and RAW. I have them in my video, and I also graded the H.264 to see the differences. The RAW recording is choppy, probably because of dropped frames and recording both types of files.
Take a look and tell me what you guys think: