As confirmed with the Yale usability study, researchers commonly explore the PUI by looking in an "F" pattern on the screen (meaning: across the top, down the left side, and across the middle area). The collection organization sidebar is an extremely important tool for researchers, but it is unintuitively placed on the right hand column. As described on page 15: "Many users did not see this sidebar
immediately because they scan the page down along the left side. Some users noted
that they expected this type of feature to be on the left side of the screen. Screen
readers must read through everything on the left side of the page before coming to
this section so right-hand orientation is also an accessibility issue."
What if the finding aid view became the dominant part of the collection overview tab, and that more details of the archival object expand within this view when they're clicked upon? As described in ANW-765, I agree that the top container listing needs to be more prominent in the list view.
An additional point is that neither view is currently that helpful in keeping track of the hierarchy for a large collection. Ideally in the finding aid view, I would like the upper hierarchy to remain visible in a collapsed position with a gist similar to Princeton's finding aids. As in, I'd like it to be more clear what series I'm in from the finding aid view, not needing to click on each item.
Yale's study also determined that the filters for search results was more effective if moved from the right to the left hand column, which is also consistent with "designing for the F".