Single shot high damage is what likho does.
Likho can 1shot stacked ravens.
Likho's missile has way better tracking than magpie, making it capable of hitting fast targets assuming they don't fly away faster than the missile.
Magpie's missile have the worst tracking of all plane homing projectiles (82 deg/s), as opposed to likho's 164deg/s or the swift's 219deg/s.
Magpie is barely faster than raven (252 elmo/s vs 246 elmo/s), making it a poor interceptor unless you happen to have your magpies already in position or your opponent flies straight at you. Likho goes at 270 elmo/s and swift without boost at 390 elmo/s. Likho can be flex aa vs most planes and all gunships.
The magpie's slow turn rate, slow flight speed and its missiles' bad homing make it a downright terrible flex aa vs plane and somewhat decent vs gunships.
The only thing the magpie really has going for it is that it has the best damage/cost ratio. Per metal, the magpie does 1.714 damage, the likho has exactly 1 and the swift's missile 0.9.
IMO the swift remains superior in large skirmishes. If you're not flying over ground splash AA (especially ettin/thresher), it's much more efficient to take a swarm of swifts, circle target a group of planes and hold CTRL before releasing, splitting the swifts between all the targets. That usually results in all the enemies getting targeted by enough missiles and guns to all get taken down. The danger of trying that with a new plane that has single shot is that short of fighting krows, you don't need heavy damage vs air and you'll run out of projectiles fighting large enemy swarms. Most air units are very brittle and any amount of any AA will take out planes very quickly.
If you want flex aa vs gunships, get likhos.
Other than krow, what would you use a specialized air single shot fighter against? Seems like an ultra specialized role that doesn't have a use unless you literally want a flying ultimatum.
EDIT: And by the way, likho is faster than raptor. lol