You mean visually? Or editing-wise like in Star Wars when they put Hayden Christensen in the end of Episode 6
Visually. For Stalker, Artificial Eye used the print from the Films Without Frontiers transfer in France. But it seems as though they did no restoration at all. It's scratched and dirty, full of artifacts, and far too soft and dark. Saturation seems really wonky at times too.
It's strange because Artificial Eye released a bunch of Tarkovsky's work on BD this past year, and were super hit or miss. Rublev, Mirror, Solaris, Ivan's Childhood were all pretty good transfers, but Nostalghia and Stalker were appallingly bad, and The Sacrifice was in between and decent.
Apparently Criterion has the rights to the much better MosFilm transfers of Stalker, The Mirror, Solaris, Andrei Rublev, Ivan's Childhood. Sadly, no The Sacrifice or Nostalghia. I love the latter, perhaps my favourite Tarkovsky, and hate that it still has no decent Blu-ray release.