Nice work Gary
This is a rather striking image.
I agree the guiding looks really good with nice point like stars! You have preserved the detail in the bright areas well, the colour balance is nice and considering the rather short exposure time, you are even starting to reveal some of the extensive surrounding faint background nebulosity
I notice there are some clean darker circles around some of the stars though, particularly noticable in the stars on top of the nebulosity, did you have to reduce one of the colour frames to match star image sizes?
Something in your processing is also giving this image a slight paint by numbers look to me, ie there are borders between brightness gradients as if it was screenprinted (do you know what I mean?). It is quite subtle but is giving the image an ever so slightly unatural look. It is most likely to be the artificial noise reduction or smoothing you have used or perhaps some filter used in the processing? any ideas?
Still, a very nice image regardless
Mike