AndreeOnline
Veteran
Perhaps "suck" is a bit of an over exaggeration, but when compared with other 4K codecs from the competitors, I can hardly say it is among the best. Sony's 4K XAVC is remarkably efficient and does not require a transcode. Red's 4K raw is absolutely brilliant as well. Both also produce very reasonable file sizes. Though I do realize the price differences as well.
The 1Dc uses an intra frame compression. It's not quite "fair" to compare its data rate to that of a inter frame xavc implementation. I don't know that much about xavc, but I think that in an intra frame flavour, it too will produce hefty file sizes. Surely better than mjpeg, but there is a large difference between saving 25 real frames per second compared to just a few keyframes in a GOP.
Checking Wikipedia, I see that xavc supports up to 12 bit, 60 fps and 4k up to 4:4:4. It can be both intra and inter frame. Very nice. Such a codec would be a welcome addition to a Canon camera.
I also agree that RED raw is nice. To me, it is probably the main advantage to the RED system: an efficient way to record raw "internally".