On the R3, I use them as an expendable point defense fighter. There are plenty of ships that need it with the proliferation of missiles, and a flight of them can be invaluable in protecting larger ships. Sure the BV may be high, but compared to what they are protecting...
As for anti-infantry, its an experiment. Its nice not worrying about bombs, and the Free Worlds League was known for oversized infantry formations so it may be practical. I probably should not comment more since I haven't playtested it in that role at all.
The primary version is an acceptable fighter. I agree that I don't like LACs, but it works with the design. Its weaponry is logical and as you said it has armor to go around.
The ER version is fun.