VideoGuys has a link to Cineform HDV Intermediate Codec image quality comparisons. This comparison focuses on multi-generational quality degradation, and how well the Cineform intermediate handles that challenge. They compare raw MT2 media with sources that have been converted to the Cineform codec, and then show that media after 10 generations of processing.

The differences are striking. Cineform beats native M2T editing, hands down.
Yes, it’s Cineform that has conducted this test…but they are careful to note the exact steps taken in Sony Vegas to duplicate the test so that you can independently verify the results if you wish. Pretty interesting stuff.