This one's minor. In switching between tab groups or possibly between tabs in a tab group, the title bar does not update to show the new file path. I have it set to show full paths. I then click back and forth between tab-group windows and it clears itself up.
Second minor issue.
Yesterday, at various times, I lost the mouse pointer. (Have not seen this before with B6). This seems to be part of the "mouse goes away while you are typing" feature. Trouble was, it didn't come back. SE was aware of the mouse pointer; I could move up and down the window to select lines "blind." I could get the mouse back by clicking back and forth between tab group windows.
Both are minor. I REALLY like the floated tab groups.