Okay, Don - I just gave 7.90.0400 a quick gander. It looks great! So, here's some feedback on the first few things that caught my eye (some of which others have brought up).
1. There needs to be an easy way to set the properties of the second pane equal to the first. By that, I'm referring to columns, column positions and widths, Date/Time formats, etc... You wouldn't want to copy "Default Tab" status or "Home" location, but all the rest of it. Aside from it being tedious to configure two panes instead of one for a first time config, it also might be common to change the parameters of one pane for a temporary job - after which, you would want to set it back to defaults again.
2. The inactive pane must have live autorefresh. I know this has been mentioned before, but it's an absolute must. Also, since this topic is up, I'll mention that there are many circumstances where the Tree does not reflect changes made by other apps, and it must be manually refreshed for those changes to show up. This behavior has been around for a while, but it would be nice if the Tree could keep up as well.
3. There needs to be a KB shortcut to switch panes. It would be nice if this could be configured both for the Tab key to include the inactive pane in its cycle, as well as for the option to use a seperate configurable shortcut. If I had to choose one type or another, I'd probably choose the Tab method - but there seems to be enough call for both methods for it to be considered.
4. When the Info Panel comes up, it resizes the bottom pane (when using Horizontal panes) - which is fine. Under certain circumstances, however (which I have not yet been able to duplicate), when the info panel is closed, the pane size is not restored, which leaves the bottom pane considerablely shorter than the top pane.
5. The Search Tabs are locked now. This is an annoyance, because it makes for extra steps to close it down.
6. Dual Trees.
Also, now that I've seen it in action, I like the method used to show which pane is active. It's subtle, which clearly has already caused a bit of confusion, but nice. In my opinion, once you know what to look for, there's no issue with making the distinction.