17mins...! I've never heard of anyone going so long with a 300D. However the results prove that it was a worthwhile excersise. Well done!
For comparison I did M83 on Friday night, but with 5x3min shots.
http://www.star-mate.com/DSO/M83_Pro2_web.jpg
Your image is brighter and has a bit more detail in the outer rings.
Keep it up.
Cheers