Orbiting using the Orbit Point Of Interest mode is useful as long as you initiate the orbit over a geometry object.
If you don't initiate the orbit over a geometry object you would expect the center of the orbit (the "point of interest") to be placed on the World Grid (or Active Grid Object), however the center of orbit ends up in a seemingly arbitrary position above or below the World Grid, which produces unexpected and annoying scene navigation.
Highly annoying
If the center of orbit would be placed on the World Grid when no geometry is in front of the cursor I believe the orbiting would become more intuitive and less confusing and annoying. At least make this a user option in preferences.
Also, the center of orbit does not detect frozen objects, which is annoying in case you actually want to use frozen object surfaces to orbit around. This should also be made as an option depending on user preference.
(Edit:)
To summarize other suggestions:
The user should be able to decide a dynamic orbiting mode that switches depending on what the user specifies for different selection levels, for example:
• If no object is selected .
• If any object is selected but subObjectLevel is equal to 0.
• If subObjectLevel is not 0 (when editing vertices, faces, etc) but no subObject is selected.
• If subObjects are selected.
Other suggestions include:
• Locking the Point Of Interest (the point won't change until you unlock it).
• Manual Placement of the Point Of Interest by clicking/snapping to things in the scene.