As of version 2.0, the perspective bar is integrated into the sidebar. I would prefer that the perspective bar to be its own entity with equal treatment to the sidebar, outline and inspector.
Firstly, having the perspective bar with equal treatment would improve navigation and navigation shortcuts.
Secondly, it would improve flexibility creating perspectives. Ie, in future versions, when window settings are included in perspectives, we will be able to keep the perspective bar open, but close the sidebar. I have numerous perspectives where I would like to hide the sidebar, but keep the perspectives bar open.
I am inspired here by Kourosh Dini’s Workflow of Perspectives. I love the idea of using the perspective bar as a workflow tool, but the current integration of the Perspective Bar into the Sidebar inhibits a full utlization of this method.