It seems to me that this item is not actually a "mount", as described, but more a "mounting platform". They provide a smooth steel disk, painted the same color as your dash, fastened securely with original equip screws, that is just at or slightly above level with the rest of your dash, to which YOU may mount a suitable "device mount". That may be a suction cup friction mount sold at so many gas stations, or a specific mount that comes with your device, etc.
Please correct me if I am seeing this wrong.
I think it may be a good choice for many that would rather have the "OEM" look of color matched steel to attach their device mount to, and I am glad to discover there are two screws holding that plate down...
I also considered mounting a "multi guage" in that spot, but now I believe I will mill down a piece of "Corian" to fill that space and make a custom phone mount.