I've come to the conclusion that it can be a multitude of different things, with some being more noticeable than others.
SO, I'd like to post my findings and discuss...here's a small list of what I've found so far that can contribute to chattering...Sorry if this is a reposted topic...I can't even read right now to do a search, so if yall don't mind I'm just gonna fill the board up with a single redundant topic.
Busy HDRI images in reflection channels.
Large Black Domes that were used for transparency raytracing being reflected onto tiny objects a large distance always. This was the most noticeable issue.
Very small procedural textures are an extreme no no! ...
A small Area light far away from objects with a shadow quality of 4 or lower can also contribute to chattering.
Higher AA levels set in bump channels
And, lastly, sometimes higher global AA settings will dampen the problem.
I know I missed a few things because my scenes may be limited, so I was hoping others could add to the list.
disclaimer: I see words...and they're kinda made into sentences and stuff...but my brain does whack when I've been up all night...so if it doesn't make sense, come back tomorrow.