I looked everywhere for info on these but couldn't find any prior to buying, so in case anyone else has been looking for information on speed on these, I took a chance and bought one (had lots of good experiences with Transcend in the past), and could not be happier. I paid $209 for it on amazon.
It is blazing fast.
Disabled anything that might slow 5D Mk III, put it on very high ISO to up shutter speed to 640, and started firing:
18/19 shot average on Large RAW using high speed (6 fps) continuous before the shutter started to stutter.
Went over 200 on Large RAW on silent continuous (3 fps) before giving up on it stuttering.
Went over 230 on Large Jpeg on high speed continuous before giving up on it stuttering.
Using an external USB 3 Sandisk imagemate card reader, it took 24 seconds to transfer 1.91GB from CF to my hard drive.