This is yet another one of those general topics where I'm trying to formulate the question but don't have enough to get that done.
I note that in many of my renderings the initial rendering passes that A:M reports tend to render pretty quick (note that this is with and without multipass on) even on the order of seconds.
The initial antialiasing pass can take about that same time.
During the antialiasing second pass things slow down considerably (a render last night took seconds for each of the initial passes but over an hour for the second antialiasing pass).
Now granted... there may be a lot going on there in that pass and some of it might might not specifically be related to actual antialiasing... although that's what it states is happening.
Also... roughness of surfaces and shiny reflections surely added considerably to that particularly lengthy pass.
I have no issues with that.
But my curiosity is officially aroused and I want to learn more about how best to wrangle this second antialiasing pass and to better understand how to manipulate it.
Any insights, pointers or references will be appreciated.
Also as an aside: Over the last two updates I distinctly detect better renderings in A:M although I am not aware of any specific changes. It could be and very likely is just me and my aging eyes but I like what I'm seeing these days. And regardless, A:M still amazes me.