Now that I have my refurbished surround system and added Atmos I am desperately trying not to go down the rabbit hole of buying movies like I did in the early 90's with laser discs. I rarely watch movies multiple times, but these new 4K UHD/with Atmos are so cool. I have about 7 movies now and I know I have to hold back.
A few things I have noticed on the 4K UHD format, the older movies still don't equal the newer movies as far as picture quality, same for sound, the newer with Atmos are better than the older with Atmos.
It seems like war and Sci Fi have the best Atmos mixes.
Some movie with Atmos mix that I have streamed seem to be weak in Atmos. For instance I love the series on Disney+ called The Mandolarian, streamed in Atmos but super weak, almost non existent in the height channels.
Any way, I certainly don't want to become an expert on movies, there are plenty of You Tubers for that.