Mon Oncle (1958)

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.

StudioCanal's 4K release is similar in encode quality, but has significant glitches in multiple frames. See comparisons 9-16 here: https://slow.pics/c/YkSVb3Ey

The pitch of the StudioCanal 4K's English audio is too high

Criterion has more extras than StudioCanal.

US Criterion 4K Blu-ray > UK MoC 4K Blu-ray > Australia Imprint > US Kino Lorber better encoding

The MoC, Criterion and Imprint UHDs were encoded by FiM making all 3 very close. The higher bitrate helped in deciding and some luck; however Criterion is the most consistent one of all 3. Imprint has some scenes with more splotchy grain while MoC is quite close to Criterion but has some more blocking in dark scenes (e.g.: comp #27). With Criterion’s superior audio, it ensures complete consistency.

From cbc: "I'm personally quite fond of the restored track on Eureka's 4K Blu-ray. It does have spots with objectively worse fidelity, but for the most part, it sounds a lot more natural and less shrill, particularly dialogue. It seems to be a new mixdown of stems. Technically a remix, so not everyone's cup of tea, but it's not revisionist like most new movie mixes tend to be"

Both Imprint (included in their set) and Capelight (on its own/individually) offer remastered BDs. All other BDs, including the one included in The Complete Kubrick, are sourced from the same older master from around 2010.