The Seraphim T3 AA is the least effective of all four of the faction's T3 AA defense. It is obviously more powerful than the T2 version, but it does not have the required oomph to take down heavy air units efficiently or as successfully as the other factions'. Note that this AA installation is far less efficient than those of the other factions due to lack of tracking in its projectiles. You may find that T2 Mobile Anti-Air Flak units are better for the job, especially since they can hover. Due to its low rate of fire T3 AA is easily overwhelmed by hordes of smaller units like gunships or even T1 bombers, so if you do build it you need to back it up with T2 flak as wel[however, the lathu-ioz fires at the same rate as its SAM cousins]. Fighter cover is even more important for the seraphim than any other faction, as the lack of tracking in its projectiles will limit it's use against T3 units.
While generally being the worst of the four T3 AA turrets, the lathu is also the most unique. Normally, seraphim units are either slightly superior to or totally different than their Aeon counterparts[their air units tend to have more health, or a side ability, like their spy plane]. However, the lathu is unique for being generally inferior to its aeon counterpart.
The second thing that makes the lathu unique is that although its projectiles do not track, they have a very fast velocity, helping to reduce overkill. For example, according to tests, SAMs would fire all their projectiles at a gunship and have overkill, but the lathu would fire just one projectile and move on to another target, reducing overkill, and since the unit would only take one projectile, its wreck might survive to provide mass.