While I have not taken actual measurements other than how far one could detect the output of the plasma tube and Phanotron, I offer this analogy for consideration.
When you turn on a standard shaped light bulb like say on a desk lamp, it fills the room with light. When you turn on a kitchen overhead light fixture, for which is installed fluorescent tubes, it fills the room with light.
The shape of the bulb did not prevent the bulb from still filling the room with light.
Consequently, both will fill an area a little larger than the size of a football field with plasma energy.
It is just theorized that the Phanotron will yield an additional focused output in the direction that the angled anode suggest.
While the near field still remains the same of 6 inches or less, the tube will provide a near field that is longer because of the shape of the tube. The Phanotron will provide a spherical near field with potentially more energy sent in a specific direction.
Physically I can feel more of an effect (subtle) when I point the Phanotron in my direction vs. when I do not from 4 feet away. Also, I can lock up my rig easily when I point it towards my generators, and while anecdotal, seems to confirm the theory.
The tube is touted as being better for full body exposure probably because the tube is long and you can get more near field exposure. The Phanotron is touted as being better for focused application and more likely has less to do with the angled anode than it does the shape of the bulb — the directional quality is just bonus.
Both will still hit the entire body with plasma energy.