The Kestrel is a heavy missile boat with one of the most sophisticated sensor arrays around. Interestingly enough, it has been used by both the Caldari Navy and several wealthy trade corporations as a cargo-hauling vessel. It is one of few trading vessels with good punching power, making it ideal for solo trade-runs in dangerous areas. The Kestrel was designed so that it could take up to four missile launchers but as a result it cannot be equipped with turret weapons nor with mining lasers.
The Kestrel can fit four missile launchers, making it an ideal Level 1 or 2 mission runner for missile specialists. As the primary missile users of EVE, you'd expect the Caldari to have a strong missile boat, the Kestrel doesn't disappoint. With a slot layout of 4/4/2, the Kestrel quite a versatile ship. Not only does it share the standard double-size damage bonus of the rest of the missile line, but it's the only one with 4 launcher hardpoints. That makes the Kestrel the only t1 frigate with 4 bonus primary weapons.
With rockets, the Kestrel has a very impressive damage output. Like the Incursus, it is able to fit a light armor tank and opt for range control, or a more robust Medium Shield Extender shield tank. Neither setup is especially tough, however the flexibility of missiles combined with a DPS output more commonly associated with turrets is nothing to scoff at.
Where the Kestrel gets really interesting however, is when it's fit with light missile launchers. While this brings its DPS output down to about the level of the Punisher or the Merlin, the Light Missile Launcher Kestrel is able to apply that DPS from up to 40km off, which is really quite impressive range for a frigate. Unfortunately the considerable CPU and Power grid required to fit light missile launchers precludes being able to mount a decent tank too, so a LML Kestrel caught at close range will generally die quickly. Of course with 40km of range to play with, catching this ship is easier said than done.
Caldari Frigate bonuses (per skill level):
[Kestrel, Tackling Rockets] Nanofiber Internal Structure I Ballistic Control System I 1MN Microwarpdrive I Warp Disruptor I Stasis Webifier I 'Malkuth' Rocket Launcher I, Caldari Navy Scourge Rocket 'Malkuth' Rocket Launcher I, Caldari Navy Scourge Rocket 'Malkuth' Rocket Launcher I, Caldari Navy Scourge Rocket 'Malkuth' Rocket Launcher I, Caldari Navy Scourge Rocket
[Kestrel, Hero Tackle] Nanofiber Internal Structure I Nanofiber Internal Structure I 1MN Microwarpdrive I Tracking Disruptor I, Tracking Speed Disruption Script Tracking Disruptor I, Tracking Speed Disruption Script J5 Prototype Warp Disruptor I Rocket Launcher I, Mjolnir Rocket Rocket Launcher I, Mjolnir Rocket Rocket Launcher I, Mjolnir Rocket Rocket Launcher I, Mjolnir Rocket Small Processor Overclocking Unit I
For anyone with a modicum of skills you won't need the Rig, but fit as necessary (they're pretty cheap at the moment.) Burn in, keep traversal high, and close orbit big ships while they miss you a bunch
[Kestrel, Target Painting Missiles] Ballistic Control System I Micro Auxiliary Power Core I 1MN Afterburner I Target Painter I Small Shield Extender I Upgraded 'Malkuth' Light Missile Launcher, Caldari Navy Scourge Light Missile Upgraded 'Malkuth' Light Missile Launcher, Caldari Navy Scourge Light Missile Upgraded 'Malkuth' Light Missile Launcher, Caldari Navy Scourge Light Missile Upgraded 'Malkuth' Light Missile Launcher, Caldari Navy Scourge Light Missile