There is no reason it should not do just as well as a backstay section of the same length, or a length of wire or SS cable of the same length. Even if you take the vendor's claim that it has a 1.2 db gain over a backstay antenna, that is an insignificant increment in the radio
communication scheme of things.
You would be best off using a halyard
of some sort to raise this antenna.
If you like paying $185 for a wire antenna like this, you can also find almost equally expensive counterpoise
'systems' that do the work of $20 worth of wire.