Most of Kubrick's BDs are flawed, as captainsolo stated. They were good for when they came out, but they just don't hold up compared to today's standards. Quick run-down.
Rating reflects accuracy to film source material, not necessarily quality.
Italicized the ones that could show significant improvement with a new version.
Fear and Desire (1953)- 9/10- The earliest of Kubrick's efforts is acceptable, restored by the Library of Congress, and faithful to the film's elements. The BD reflects the fact, though, that the elements are not in as high condition as those of the other film.
Killer's Kiss (1955)- 9/10- A nice transfer from Criterion, very film-like. Only needs lossless audio.
The Killing (1956)- 8/10- Has some chroma noise but is otherwise all right.
Paths of Glory (1958)- 10/10- Criterion did a good job on this one. It's sourced from a UCLA restoration, I believe. Probably the best looking Kubrick Blu-Ray.
Spartacus (1960)- 2/10- An unmitigated failure in almost all respects. It is DVNR'ed to the point that the figures start looking like wax, and one gets the uncanny valley effect. It was taken from an old transfer ridden with scanner noise. To add icing on the cake, the color restoration work, based off of an IB print, done by Robert Harris, has been completely ignored. The audio prevents this from having a 0/10.
Lolita (1963)- 8/10- There aren't really any problems with this one. I think the transfer could be slightly improved if done more recently, though it is perfectly acceptable to be honest.
Dr. Strangelove (1964)- 8/10- It looks all right to me, about the same as Lolita. I'm not sure if the 4K restoration running in cinemas was used for the BD. If it wasn't, then that would likely make an improved BD.
2001 (1968)- 8/10- The detail is all right, though it could be greatly improved due to the large format elements of the film. For a reference to how nice 70mm elements can look, watch the Lawrence of Arabia BD. As more knowledgeable minds than mine have covered, color timing is off; proper color can be found on the Criterion LD.
Clockwork Orange (1971)- 3/10- It looks pretty bad to be honest. The color timing looks off. It does not look film-like at all, very soft and digital with some slight pixelation. Contrast is weak. Clearly, it is a master made for the DVD era that would compress easy and is bright. There's a 4K restoration already made and transferred; clips are on special features of the newest BD, which is a pity when one sees them in comparison to the main feature.
Barry Lyndon (1975)- 7.5/10- It is slightly horizontally stretched compared to the DVD and LD, but it might actually be more accurate, I'm not sure. The aspect ratio is 1:78, despite the intended aspect ratio being between 1:66-1:75. To be perfectly honest, though, 1:75 and 1:78 is hardly a world of difference, as long as your overscan is off. It is likely many projectionists, lacking the proper plates, ignored the instructions and screened it as wide as 1:85. The BD is very colorful and film-like, with a healthy amount of film grain, probably the best looking of Kubrick's color features. May be the only BD-era transfer of a color Kubrick film.
The Shining (1980)- 6/10- It could use improvement. The picture doesn't look that film-like and assumes a more video-like appearance. The grain isn't there, so it would compress better... for DVD, that is. Detail survives though, relatively speaking. Contrast is lacking, and the brightness is too high, detrimental for a horror movie. The color timing is flawed for some reason, and correct timing can be seen in the HD documentary "Terror in the Aisles." A BD-era transfer would do wonders. It's also bothersome that the BD doesn't offer multiple cuts by seamless branching for the European Cut, which was edited by Kubrick himself. Aspect ratio should be 1:85, ideally.
Full Metal Jacket (1987)- 7/10- It's basically like the Shining but without the color issues. The brightness is too high like that one, and the contrast is too low, as well. Aspect ratio should be 1:85, ideally.
Eyes Wide Shut (1999)- 6/10- Technically, this looks like an all right BD, with contrast and color natural-looking to the normal viewer's eye. But, it ruins the aesthetic of the film. The film was supposed to be grainy with deep saturated colors. However, this was made for the DVD era where such grain would have been a complete mess with MPEG-2 Compression. That being said, in the age of AVC BD, this could be presented properly.