Harvey Parry

The 4K discs in both Criterion and Imprint sets are FiM encodes, but low-passed. The compression is better, but some of the grain is lost. Difference is pronounced in screen caps, but not likely to be noticed during playback, without a reference to compare it to. Comparisons

All discs use the same source transfer. It's not of the highest quality, and it includes some slight distortion, looping, clicks, pops, and hum. Criterion cleaned it up for their release, but unfortunately also lost a lot of fidelity in the process.

MGM NTSC DVD doesn't seem to have some of the more prominent distortion and has slightly different EQ but is otherwise the same.

The Criterion Complete Kubrick and Imprint 1953-1957 sets include remastered BDs. All standalone releases are from an earlier master.
Arrow UK Blu-ray has an exclusive isolated score & effects track. Kino Lorber and Imprint have an exclusive commentary each.

Imprint Australia 4K Blu-ray has slightly better compression than Criterion 4K Blu-ray.

The master in DV looks all but identical to the Criterion’s HDR grade. Detail-wise, FiM’s encode looks like it uncovered a tiny bit of extra high-frequency information that got filtered on the Criterion. See nicolas review

1990 Criterion LaserDisc/1993 MGM LaserDisc/2002 R2 MGM DVD are the best. See blah-ray https://blah-ray.blogspot.com/2018/01/raging-bull-1980.html

Imprint Australia 4K Blu-ray has better audio than Criterion 4K Blu-ray, from nicolas:

I believe that what’s on Imprint’s 4K is one of the good mixes MGM and Criterion released during the LaserDisc days. Music is powerful and detailed, dialogues have excellent fidelity and ambient sounds have perceptible depth. I compared the "new" 2.0 with the anemic 5.1 as well as the Criterion 4K mix and could clearly hear the improvements.

Included in the Complete Kubrick box set with FiM encode of the same master from the Universal release without the filtering.

DTS:X mix on Universal 4K Blu-ray most closely approximates original surround mix

Criterion DVD and Universal 4K Blu-ray has additional features not found on the Criterion 4K Blu-ray