I think it's pretty good. I did a similar thing in the past and took a single 5 min exposure with an unmodded 40D.
The image is here
http://www.iceinspace.com.au/forum/s...ad.php?t=31602
The comparison is interesting. My image isn't as red but it is an unmodded camera. The exposure is 5 times longer but both images have saturated stars. Eta will saturate with a 5 second exposure.
It's only the S/N that suffers with the short exposures of bright objects like eta Car.