RF Royce has been offering conical-shaped mirrors for a while now. He recently posted a note on his website (www.rfroyce.com) saying that even 8" and 10" versions will be available soon. He claims that no mirror cell is required with such a mirror... only that it be bolted to the bottom of a mirror box or other substrate. So, even though the mirrors are more expensive (~300 dollars extra for a 12.5" model), the total extra cost wouldn't be a lot more if you factor in the savings of a good mirror cell.
It seems there could be substantial improvement in cooldown time with such a mirror, which is the main consideration that piques my interest in such a product.
Anybody have experience with (or opioions on!!) such a mirror?
Thanks,
Duane