I thought this might go in its own thread so everyone who's interested in this stuff will see it.
I've made a page that shows the dramatic difference that proper cooling on a 10" newtonian can make. The page is here:
http://www.acquerra.com.au/astro/cooling/ballarat/
Apologies for the videos being 3Mb in size, but I needed to use a codec that preserved as much of the video quality as I could.
As you can see the difference is not subtle.
Comments welcome.
Bird