I use workspaces with clients and brand the workspace with the clients logo and brand colors. This used to show across the top of every page within the workspace, but a recent update has removed this so that it only appears when you have the "workspace panel" open.
The result of this is that 1) the logo looks odd in many of my workspaces as the background colour which it "sat on" is now just grey, and 2) it no longer feels like a client branded experience, it's not obvious that the color in the left hand bar is "their color", and 3) most importantly it is not obvious at a glance which workspace I'm working in. Clients can have similar brand colors, or even have multiple workspaces. They also have similar sheets within each workspace, so the logo made it obvious which one I was looking at. You've removed a simple but effective feature by taking away branding at a sheet level and I would urge you to look at ways to bring this back without impacting on the screen real estate.
Thanks