To be able to compare 4k77 with other editions of Star Wars, I took the frame 5032 (GOUT-synced) of 6 different versions: 4k77 (2160p), SilverScreen Edition 1.6 (1080p), BluRay (1080p), Despecialized Edition 2.7 (720p), GOUT DVD (720p) and 16mm (480p)
I adjusted the proportions of each version so that they fit and the comparison is visually effective.
The result is available here : http://www.framecompare.com/screenshotcomparison/FBMFNNNU
In my opinion, the accuracy of the 4k77 version is similar to Blu-Ray and 4k is not really sharper than 2k (4k does not help much given the grain on the film).
This new 4k77 version has very natural and less aggressive colors than the BR or the DeEd 2.7, but the SiverScreen Edition(TN1) is still my favorite because it is less cropped and keeps the full width of the film (there is 11% more image than on the 4k77 version).
(I also compared the different versions laserdisc, VHS, VCD and 8mm, but I can only upload 6 images on framecompare).
Percentage wise, cropping is about the same as for the LPP - it was cropped to 2.35:1 which is less than the cropping at the cinema in '77 with was 2.39.1. The top and bottom and the junk on the right would have been removed by the projectionist too. It is also worth pointing out that the LPP used for the SSE had much more picture information on all sides than the tech prints:
http://www.framecompare.com/image-compare/screenshotcomparison/KL6WNNNX