I am aware that flucon was mainly touted as a treatment for bryopsis. However, people have also suggested that it will take out other forms of hair algae within 3-4 weeks. My experience indicates that this is not true, at least not at the dosage suggested (my dosage was actually higher).
My surviving alga has a branching filament structure like bryopsis, but does not look bushy or fernlike. Given the numbers of GHA and bryopsis species that are said to exist, I have no way of knowing what exactly it is.
I'm glad I used flucon because, as I said, it did get rid of two other varieties of nuisance algae. Given the level of uncertainty around algae ID, I think flucon is absolutely worth using, but I suggest that people use it in conjunction with other treatments. I have very little GHA in my bowl because I never stopped doing peroxide spot treatments while I was treating with flucon.