I don't see any noise. If you do, and are not happy, then make yourself your own scene :)
I note the smiley so I know you don't mean that in a nasty way -
I don't know nearly enough about Corona right now to even pass judgement on anyone's scene
I am at the empty room with a tea pot and sun system in it sort of stage right now. :)
I thought your demo scene was excellent and I have enjoyed looking at the settings - the materials and playing with the renderer
It has helped me get a good understanding of the renderer in a very short space of time.
I can see the effect the portal has on the image and I now understand its about the way the direct light penetrates the scene.
I have learned from this and I can now make my own scene to start using as my own test bed.
I hope I can post that scene up when finished for other people to test with.
Lets see where I get to.
Thanks again for your help -