I like the blue colouring and the galaxies showing in this scene. There are quite a few to check out. I like the expansive field of view too, showing a lot of this object. I don't think there is a gradient. I found when I imaged a portion of this object that my colouring looked consistently like what you have here but you have a little more saturation that I do. It's a tough object that likes plenty of integration time if one is using short subs (10 minutes or less) with a narrow aperture, so kudos for producing a pretty noise free image.
What I think detracts this image is the star shapes. The smaller images don't show any problems but the hi res image shows stars that are elongated to some degree or another over the entire field. It's particularly bad in the top left corner and that is what you see straight up when you open the image.
Like I said though, there is plenty to like.
