Well, most HF's I'm flying are fine as they are. To the extent of me flying almost only HFs, that is.
Specifically though, two fighters that need fixing need to be adjusted, those being:
The Katana (Blood Dragon HF) needs to be made identical to the Chimmie (Kusari lawful HF). It's currently the inferior of both, when they should be identical statswise.
The BH shipline that Lyth mentioned is actually a thing. The Hammerhead needs fixing. It's a HF that turns slower than not only its VHF equivalent, but slower than even some bombers. No wonder everyone is using only Mantas.
Edit after the Ninjas: Please don't make all HFs 'utility'. The HFs with 6 guns are mostly fine, really.