Do faster cards improve image quality with the Canon 7D?

Over at the _mxr blog, there's a comparison of Cheap Compact Flast vs. UDMA cards. I've read posts before on forum's that hint at the faster cards resulting in better video quality (the theory being that the camera knows how fast the card is, and adjusts the quality of compression it is using.) But I've never seen any actual documentation of the cameras doing that, and it's interesting to see even some simple tests/comparisons like this:

Conclusion? In my opinion rolling shutter stayed the same, bitrate didn’t significantly change and color stayed the same. Only thing that is annoying with slower cards is that they need some time to buffer.