The Theatrical BluRay is soft and has plenty of DNR in it.
DrDre already did an 4k-Upscale of the Theatrical Bluray. The Results are okayish imo. But it cannot compete with this 4k-Upscale of the Extended Cut.

I did a comparison of the 4k-Bluray and 4k-Dremaster. There are many shots where the Version from DrDre Looks sharper and more detailed, the rest is a tie imo. But I don’t think there is any benefit of using the 4k-Bluray as source.
The Main reason for the Remaster of the Extended BluRay is because the official 4k Release was dissapointing to say the least.

The Colorgrading is Personal preference.
The 4k-Bluray might look more neutral but I prefer the colors from DrDre’s release which as far as I understand is how people saw the movie in Cinema. Some scenes have stronger color tints but it all fits the narrative.
Especially the Shire scenes have a warmth and colorfulness that is not present in the official 4k Release.
And the Shire should be exactly that:
A place of comfort and warmth.