In particular with the 2nd image you increased contrast at the expense of the mottled detail in the first post. I guess that is not such a good idea with nebulosity and I've had that problem with images of the Orion nebula, for example.
I guess it works better when there are only stars and no nebulosity. But it's all a matter of taste and what you want to accomplish with the image. Or maybe you can tone it down and find a happy medium.