i just made a test run with a dummychar. and missiles are nicer than i thought they are - yet cost too much.
i did some missions against hammerheads BHGs. loadout was 4 diliberators + 2 sidewinders. it worked well - i was able to shoot down their shields in one or two salvos and then take out their hull with like 4 missiles.
a lot quicker than it would have taken me to do it with guns. however - in the end, i had like 8 missiles left and headed back to crete to claim my mission reward. sadly enough - the mission reward was less than it cost me to refill my ammo.
so, yes, missiles are not too bad, provided you have a good ping, i usually have 55 - 78 ping. they guarantee a quick kill. but don t pay off at all. the tracking of the missiles was OK - but worked best, when the enemy was charging towards me. when the missiles actually had to track and follow the target, they often missed or only scored a fraction of their original damage.