Well, in my opinion, the last one is a LOT better. Not so drastic with the oversaturated colors, and not so much contrast, which would eliminate so many faint objects. Now, a lot of faint stars are visible. I'm certainly no expert on post-processing, but I like this much better. You learn as you experiment, so keep trying different things to see what you think works best. Don't limit yourself to the default settings in DSS, either. Experiment with all the controls to find out what they do. You can alter the appearance of your pictures a lot with those controls. I usually save about 6 to 10 versions of the changes I make after DSS finishes stacking mine. Each time I make an improvement, I save it, just in case it's the best I can do... and then try other adjustments, and save another one.
I think most camera lenses suffer from vignetting - producing images that are darker around the outside than in the middle. My D5500 has a "Vignette Control" in the "Shooting" menu, that increases peripheral illumination. Don't know if your camera has this setting or not, but it helps balance the illumination all across the image. Even with the vignette control set to "High" my photos are still darker around the outside edges than in the middle. A lot of imaging software includes adjustments to vary the amount of lighting around the periphery of the pictures, as well.
But, even with the vignette control, it would be beneficial to learn to take "Flat Frames", which would help with the vignetting during stacking.
Still, you're making some serious progress. Keep at it! And have fun!