Well, the plugin was born out of my own requirements, which it has suited just fine for me.
It has evolved during this time and perhaps the common usage scenarios are different, but I wouldn't go as far as to give it a "Bad UI" rating.
If you don't like it, I do welcome suggestions and have implemented almost all (I think) of what I've received in the forums.
On a fresh install, the initial instinct is to click on the "Home" tab. There is nothing on the settings page telling you "hey dummy, add a folder to move" so the home tab link will do something. Perhaps you could move the "which folders do you want to move" section to the home tab, so at least you see some action when you initially click on home.
Also, I think the common usage is now to completely clean off a specific disk, for whatever reason, with all the folders included. Maybe populating the home tab with a share level deep drive list with check boxes for drives or individual shares as source, and valid destinations with checkboxes as well. For example, I could check just the movies on disk1 and have the destination be disk2,3,4 or I could check the entire disk1 and send it across all the rest of the drives.
It seems a little off to want to empty a specific disk, but step 1 is to pick which folders I want to move. Since unraid's share system by default doesn't force specific disks for a share, it's conceivable that a user may have no clue which shares are on a drive when he opens unBALANCE, he just wants the drive empty, and expects to be shown a list of drives that can be emptied and a list of possible destinations.
Thank you for your work on this, it's truly the go to plugin for novice friendly disk level data management, it's a function that should IMHO be Limetech's responsibility, but hey, that's what the community is for, to fill the holes in basic functionality.
Thanks for the comments jonathanm.
That's something I've thought about ... moving the "file explorer" currently on the settings tab to the home tab, under the currently selected source disk, populated with whatever folders are on the disk.
This is what I'll be working on next, as time allows.