Very interesting to see what 20 minutes gets you on a DSLR. To be honest I'm surprised it's not more exposure or even bleeching out, perhaps that's why SBIG still sell STL1100's
Anyhow, excellent image - much better than the blue and fainter versions I will achieve with my unmodified 350D.
Congrats on the guiding, I know what a pain it can be sometimes, most of the time, .... good guiding is no small achievment.
Roger.