The advantages of this antenna are
1}Broad bandwidth
...Yes, they are fairly broadbanded. But also has reduced radiation efficiency the further from the design/resonant frequency that you go. Fact, see ARRL Antenna Compendium #3 (I think it's #3).
2}Almost unaffected by environment
...Nope, sorry, just not true. It's affected just like any other antenna as to it's environment (nearness to objects, height, etc.).
3} Positive gain with reference to a common dipole operating under the same relative conditions up to 3.6 db
...It's a 1/2 wave antenna/dipole. How can it have gain over it's self?
4}Greatly attenuates harmonics
...Uh, yeah, just like any dipole. In other words, no it doesn't.
5}Substantial decrease in static charge build-up
...Don't bet on it!
6}Non-directional. (as a inverted V)
...Depends on mounting height and the angle between the legs.. An inverted 'V' is not the same as a 'drooping' dipole, don't confuse the two. Very few inverted 'V's are actually inverted 'V's. Most are 'drooping' dipoles.
Bazooka antennas have a greatly enlarged/exagerated reputation. They are nice antennas, but nothing really 'magical' about them or their abilities. They also have draw-backs, as in they weigh more than an ordinary dipole, require stronger supports, and cost more.
- 'Doc
PS - Good advertising department!