When using the sidebar layout of Task 3.0, I am able to multitask like a champion, BUT
It is visually messy to not have a bold dividing line between the content that is my task and the content that is behind it. Perhaps some sort of bold line would help with this, so that the sidebar looks and feels like a separate element from what I am also working on. In the GIF below, you can see that the line is very faint UNTIL you click to drag and resize. The line that glows when dragging is great, let's have it there at all times! (or something similar).
Also notice int he last GIF that we DO have this kind of contrast when viewing other sidebar layout items like the People viewer, and it looks great, but is likely too much contrast to copy for this particular scenario. It is more like an overlay than a sidebar.