Very very nice Hugh, love the colour and detail.
I've just started using the Masked Stretch tool to soften my bloated stars, does a great job I think. The "Morphological Transformation" tool will also reduce star sizes.
Masked Stretch Tutorial
Also try the "Dark structure enhance" script with a mild setting. It can really make the dark dusty bits pop. Its in "Script - Utilities" from memory
(I'm at work ATM)
Cheers
Rod