Thanks everyone for all the feedback.
This was taken last Saturday just north of Brisbane and being just after sunset the seeing was a bit hit and miss, although it was a nice cool evening for the camera.
- Scope: Skywatcher Esprit 100 f/5.5
- Camera: modded Canon 1100D (with Baader BCF filter fitted)
- Mount: EQ6
I'm currently evaluating PixInsight and so far I'm intrigued by some of the functions, it seems a pretty powerful package. Both stacking and stretching seem to be kinder to stars than my previous workflow, so I'm keen to learn how to apply a star mask...just haven't got around to it yet
I can see what you guys mean by the mottling, but I believe this to be an issue of resampling and or compression for IIS

I've attached a crop of the Keyhole (100%) after just the histogram stretch and before attacking it ACDNR or HDRMT (and baking the saturation to 250 degrees

)
I had my camera modded about 6 months ago and since then the weather has been pretty awful most of the time, so it's only recently that I've been able to get some proper (more than 1 sub!) test data with it, and of course the new scope. The red push in the images after modding I found quite tricky to deal with satisfactorily using conventional means, hence the interest in an alternative approach.
Any tips and tricks from more experienced processing guys like yourselves is very much appreciated, especially to maximise my evaluation period, as it's a tough sell to the other half for a piece of astro software of this value, as opposed to something tangible like new glass