The cover art isn't that attractive but is the disc/picture quality up to par with their 90s releases?

Depends entirely on the source material as it always has with Criterion.

Casablanca: Special Edition #73 (1942) [CC1179L] and Hidden Fortress, The #11 (1958) [CC1111L] both look incredible in my opinion, but then you have something like Dr. No: Special Edition #124 (1962) [CC1234L] which came out in the 1991 and looks horrible in comparison.

Still, I'd say the average Criterion release (rather it's on LD, DVD or BD) will still look way better than most everything else out there.