I guess graded means image processing to get the "Peter Lik look", increasing saturation, doing some tone mapping. It is indeed a stunning picture, but you cannot really judge the EPIC's performance from that reduced size and processed picture. "No noise reduction" it says, but reducing the size of a picture will exactly do that, reduce noise since it is averaged into the remaining pixels.
As far as I understand from reading in the referred thread it is shoot with a model having a 30x15mm sensor with 5120x2700 resolution, stitched from a number of horizontal shots (probably three with large overlaps to be able to stitch without getting seams where stuff moves). The final image is probably 7800x2700 pixels. An IQ180 can do that in one shot with appropriate focal length, but would require longer shutter speed since IQ180 is not really a high ISO tool.
The suggested 10 feet print size would yield 65 ppi. Ok for a large viewing distance I guess :-).