Grouped (staged/un-staged) table view creates serious usability problems

The new grouped table view is an endless source of confusion and mistakes. The old system was so well done. I drag an item to the top table and I can clearly see what's happening. In the new version, SourceTree is always trying to keep something selected and it is always the wrong thing. I am constantly confused about what I am looking at. Because the table changes every time I check something, my mouse is always in the wrong place. I just accidentally staged everything because things are always moving around. This is just poorly done. It's not even a question of not liking change. This is just not very well done. But I should come with solutions, not problems, right?

Go back to two table views that are in a split view so that they don't change sizes. When I check un-staged, it goes to staged but its tableview does not resize. The next un-staged item would move up but the group header does not move. Importantly, the item that was selected, goes to staged and stays selected so the thing that I was looking at does not change. Just as important, the table view header does not move so I don't accidentally stage/un-staged everything.

I am a big fan of SourceTree but even filing this issue was painfully difficult. I hope that some usability improvements come soon. Overall, the 1.9 release is quite good but this stage/un-staged table is killing me.