Not bad Fred, an enjoyable image.
Although I haven't imaged it myself, my impression is that even though it is a reasonably bright galaxy, M81 is a lot harder to image than people think. It is a very subtle galaxy, a bit like NGC 6744 in Pavo, with subtle features and gentle colour gradations that are hard to render with a truly natural result it would appear? There are very few images of M81 that I have seen that don't look obviously processed with dodgy and harsh colour gradations and/or obvious masking to bring out the core and over sharpening to reveal those fine subtle details....but here are a couple of good examples to work from:
Modest gear:
http://www.dsi-astronomie.de/M81N.html
High end gear (and by a master image processor)
http://www.rc-astro.com/photo/id1025.html
Nice international work Fred
Mike
Mike