Ok, now this one is absolutely rip-roaring jaw-hangs-open "Holy F---!" gorgeous. The kind of image that makes me sit here for ten minutes just looking at the pretty.
That said, the critique:
The color balance here is very good. You said this was a crop of the origional. Good crop. You've got good flow and good composision here...a kind of inadvertant spiral with the cropped area. There's also good movement. Something is happening in this picture and is continuing to happen once we leave. We won't get much a clue what that is, but we know it's there. Good job on that.
There's a patch of light blue color in the upper left corner that's just kinda "there". It might be something in the larger picture, but all I have to judge by is this patch. It draws the eye away from the orangy center of the nebula, and is so amorpheous that it has no shape to draw the eye back. My guess is that it's one of the other nebulas, but it's still a distraction in the crop, reguardless.
Amazing work. Excellent job.