I finished watching the imprint Magnificent 7 4k/blu-ray boxset.
The Magnificent 7 is the only movie that comes in 4k in the set and it does not look better than the Shout! 4k. So you may want to hold on to that one.
But the three blu-rays of the other movies look good.
For sure you have to own the Shout! version as it looks & sounds better than the 4k that comes in this set.