Also Paul to put it in perspective I think your image is quite a bit better than this image I took about 1.5 years ago with an RCOS 12.5 inch, Tak reducer (I think or it may have been native F9) and STL11000M class 2 camera with Astrodon filters and 3:45 total exposure:
http://www.pbase.com/gregbradley/image/96619186
Not to say the RCOS 12.5 was being used to its maximum by me but that is from my dark site which I know has awesome super dark and stable (mostly) skies.
Greg.