Flak is OP
Flak is fine against fighters.... BUT ,IS grossly OP against other units. Espesialy TEC and vasari flak.
Tec due to higest hp /cheapest cost and vasari due phaaaaase missiles and charget missiles.
That said: Flak is fine against fighters
Why? Well...
It is night impossible to remove flak from the battlefield due to near immunity to LRF fire and STUPIDLY hig hp... best hp/cost ratio of all frigs and cruisers.
So flak that is nearly unconterable is now a permanent deterrant from using fighters. This leads to 60/40 ratio in LRF/Flak fleet composition wich is now the "way to win". You cant use LF's due to LRM precense and you cant use fighters due to 75% building penalty of flak. HC's are only option, but by the time you get to that point, it is usualy too late.
Sollution?
Nerf Flak HP 50% and lover the armor a bit. It is still usualy most ignored unit in the field, but atleast now it whuld be removable, not like 1200HP 300 shield gardas are now.