[Shiraz (Ray)]

hi Peter. be interested to hear what you find if you do manage a side-by-side.
Thought about it a bit more and the corrector plate of an SCT will try to radiatively cool to the night sky temp (it has high emissivity at thermal IR wavelengths), so you will also need a dew shield to minimise the amount of night sky visible to that element, regardless of what the tube does. The dew shield should also be foil wrapped so that it does not pour too much cold air onto the corrector.
Regards Ray