The border around the toolbars/panels in Rhino 8 are much thicker than in Rhino 7. I’m not sure if that should be considered a regression, but I certainly prefer the thinner borders in Rhino 7. I looked through the advanced settings, but didn’t find any values for customising these.
The indicated lines in Rhino 7 are indeed borders. In Rhino 8 there are no such borders, except around the viewports. For the rest, the UI elements should be separated by a 3 pixel padding (@100%). The thin lines under the grippers are not borders, but a separation line between the gripper and the toolbar it belongs to, and this should be a 1 pixel line.
I do see some issues and inconsistencies on Windows with how these lines are rendered though. On Mac it seems to render better.
Indeed that does appear to be the overarching issue, and I would also agree that the worst offender is the new thicker “padding” around the viewports. That said, these too appear inconsistent in thickness (here with the frame background colour set to red):
Yes, I made a few YT’s today that should address these. Most of them are specific to Windows and the first is an issue related to Windows scaling. RH-81331 Toolbar grippers have odd shading RH-81332 Padding between standard toolbar and command line RH-81333 Padding around viewports is too large RH-81334 Vertical tab on docked containers is a pixel too short