Thanks for your insights and help. I continue to have this strange behavior concerning rendering times: I tried in each and every way, but I keep on getting faster times with Premium. I tried also with other images, so ok, I think I should consider me lucky and take it as a Bryce gift! :) As for your opinions about when to use the different AA modes, thanks a lot: it's a section not so well covered in the docs, and now I've a way clearer mind about it. --Stefano