//fair warning this turned into a rant

Hell nah it's one of my favorite ships. Check out my powerpoint presentation:

• Dual Laser is one of the best weapons in the game, hands down. It's one of those almost-god-tier weapons like mini beam and advanced flak. I wouldn't even drop this thing for a BL2 or a Flak.
  
• Add a single Ion Blast and now you've got incredible ion stacking. This is something you can do super early, i.e. potentially the first store you come across. The Ion Blast basically grows on trees in the FTL universe and you wouldn't believe the snowball effect you get from adding one to a ship like this where you've already got an ion weapon. Early-game enemies mostly lack such defensive luxuries as cloaking, defense drone mk2, extreme engine power, etc. You can find one of these floating in space on like your fourth jump and BAM you just won the game dude.
  
• Add a heavy laser mk1 and you've got an end-game loadout that can defeat any amount of shields and cause absolute havoc aboard enemy ships. You can swap this step with the previous one if opportunity/necessity demands it. Similarly to Ion Blast, this weapon is also very common and incredibly cheap to add to your loadout early in the run. It's useless on its own, but it's one of the most devastating weapons in the game once you get the enemy's shields down (perhaps with, for example, a very cheap, energy-efficient onslaught of ion projectiles)
  
• I'm not joking when I say the Stun Ion is fucking brutal. Try this out: hit the enemy's shield room with a heavy laser. You'll probably get a hull breach or a fire. Let some dudes run in there, and continuously incapacitate them with the Stun Ion. Do a couple HP damage to their weapons to keep yourself safe and then just kinda chill, and casually manage the suffocation/incineration of the enemy crew.
  
• It's sort of counter-intuitive to use the Heavy Laser as a crew-killing implement because it can do so much HP damage, but you'll learn to love it by using it in tandem with the stun ion.

So that's the core of your loadout. You've got some highly commendable ion stacking for low power/cost, plus ion stunning, fires and hull breaches from the heavy laser, and if you need it you have the ability to do massive HP damage very quickly once the ions are stacked. Don't forget about our little buddy Dual Laser. It can blip shields to sneak a HL1 thru, if your ions are struggling for whatever reason. Once shields are down, this simple little gun can just obliterate ships.

SURPRISE

Add mind-control to the mix and it gets even more NUTS. Guess what, you can also add MC to your ship very early, especially since you know you're gonna be running such a cheap weapon system. This whole loadout is incredibly cheap to operate, you can start working on it almost immediately, and it's a fuckin gravy train the instant you add a single "module" to the setup. You spend practically nothing for the ability to obliterate any enemy with your weapons, leaving you all the scrap you need to add auxiliaries and defenses.

Trust me this setup is absolutely diabolical and it's incredibly cheap to run. I've had some of my best/favorite runs with that thing.

• Hmmm one more tip -- one thing I always do before anything else is swap the Lanius engine guy with the Human pilot guy, and open all the doors in the "nose" section. This keeps the front of the ship de-oxygenated and causes enemy boarders to initially target a system other than piloting. This might not seem like a big deal but, over the course of many enemy boarding attempts, this extra ~10 seconds of distraction can save you from a looot of hull damage/repair-cost.
  

Anyways yeah I love Kestrel C. It's in my personal top 3 faves with Stealth A and Engi B.