When using the High Quality viewport setting with a background, reflective materials get nice approximative reflections in the viewport. This helps bring out the shape of metallic surfaces that are dependent on some kind of environment.
The problem comes when changing the background display mode from Use Environment Background to for example Use Customize User Interface Solid Color, the background reflections in objects disappear and the surfaces becomes mostly black.
It would be useful to be able to hide the background image in the viewport but keep the reflections on object surfaces. The background can sometimes be distracting when working with scenes so it would be useful to be able to disable it yet keep the surface reflections.
With background visible
With no background visible
Desired result (mockup)