So I've gone through and compared the new Blu-ray's to the 2011 Blu-rays for Episodes 1, 4, 5, and 6. I do not have a 4K TV or Atmos. I have a calibrated 60 inch plasma and 5.2 sound. I had both discs playing at the same time on two different players, paused and watched various sections comparing the two releases of the films.
I will preface it to say that the DTS-HD MA 6.1 audio on the 2011 Blu-ray's absolutely smacks the **** out of the DTS-HD MA 7.1 on the Disney Blu-ray's. In every conceivable way, the 2011 mixes are so much more dynamic, enveloping, and authoritative. The Disney releases aren't as bad as stuff like Ultron or Black Panther, but they definitely feel limited in dynamic range.
With Episode 1, I generally couldn't find much difference in PQ, aside from it looked like the DNR seemed a little more intense on the Disney release. The 2011 Blu-ray seemed a hair more natural. I just skipped comparing Episode 2 and 3 since I can't imagine there being much difference given how they were shot.
With Episodes 4, 5, and 6 is where things get kind of problematic. In some instances and scenes, I prefer the color and contrast on the Disney release. I like how clean they typically look, but there's just as many instances where the image looks washed out, lacking in proper color saturation. On the Disney release, Hoth looks more beige and almost warm, when it should look cold with whites and blues, like the 2011 disc. Tatooine in ROTJ doesn't look warm, but washed out. And wow, did Disney just slather on the DNR with these releases. Hair, fog, smoke, and even the puppets have much more detail on the 2011 releases. Jabba, for instance, has much more detail on the 2011 disc. I can see the wrinkles in the rubber puppet. On the Disney, it just looks soft and smudgy. During those instances on the Disney release, it just becomes a smeary mess, complete with frozen grain. The 2011 Blu-ray's are not perfect and might be a bit noisy at times, but there's not much DNR and in general, I prefer the overall look of them. Add that with the vastly superior DTS-HD MA 6.1 audio and I think I'm just going to stick with those versions when I view them. The 4K discs might be different, but given that I've heard people complaining about DNR on those releases as well, I can't imagine them looking much different.
Also, the packaging sucks on the Saga boxset. This is not the proper way to store a disc!