Of the 4, "Forever" has aged the worst. "B&R" seemed mediocre at best to me in 1997, but I actually mostly liked "Forever" back then.
Now? Not so much. It has a few good moments but every time I watch it, I like it less and less, and I find it more difficult to recall why I enjoyed it in the...
"Returns" is easily the best-looking of the 4 4Ks, but it was also easily the best-looking of the BDs, so that should be no surprise.
"Forever" and "Robin" are much bigger improvements on their BD counterparts, IMO...