Thanks for the lovely comments everyone. I too am constantly amazed at just what is possible with relatively modest gear and dark skies
That said, there are some equipment issues still to work on (eg some star elongation in the bottom left corner, I cropped out the worst of it), dew has been a bit of a problem and I've noticed that the optics could probably do with a clean at some point as well. I'm still learning the ropes with PI as well. Guess it just means that there's still lots of room to improve and optimise, which is all part of the fun
Rick - I took the plunge and just moved up to PI v1.8, so will have a play with TGVDenoise.