This HD HFR mode is supposed to offer Canon users the equivalent of Sony A7RII/A7SII slow motion. It's not a replacement for 150fps on a Sony FS7 or an FS700 with the Odyssey!
On that level, I think it looks just fine and perhaps even a little better than the A7SII, which has a tendency for bad moiré at 100fps and above. Just look at these screen grabs from the 1DX II Forest video from above:


The detail is truly magnificent here. I think it is obvious from these screen grabs that this is legitimate 1080P and not 720P. As for line skipping or pixel binning, it is not like what it was on the 5DII. There is actually some downsampling going on here and it is far more advanced than the pixel binning on previous generations.
On that level, I think it looks just fine and perhaps even a little better than the A7SII, which has a tendency for bad moiré at 100fps and above. Just look at these screen grabs from the 1DX II Forest video from above:


The detail is truly magnificent here. I think it is obvious from these screen grabs that this is legitimate 1080P and not 720P. As for line skipping or pixel binning, it is not like what it was on the 5DII. There is actually some downsampling going on here and it is far more advanced than the pixel binning on previous generations.

