I did and A/B comparison with my Canon 5D and STL11k, As they say a picture can say a thousand words, and the pictures are here
http://www.atscope.com.au/BRO/tutorials/dslr.html
If the Canon was exposed for 90 seconds, i.e. the time it took to get the RG&B channels out of a Mono camera, then it would have performed better, but that was not the point of the exercise.
I was curious to see how the two cameras would deal with the same amount of (limited) flux, and was admittedly surprised by the obvious differences in signal and noise between the two.