Not sure what FHD is?
But I can tell you this, the 4k Blurays are superior to the 2011 Blurays is detail and in color.
However there are still issues, just different ones. The colors aren’t good, they just aren’t as bad as the 2011 blurays. At least they don’t have the crushed black and clipped highlights of the 2011 versions so they can be corrected to look much better.
They also suffer from too much DNR but again not as badly done as the 2011 blurays.