Didn't kill either (though I did take down both their hulls a bit). That said, I did convince the commander to leave the system; which to me, is a success. And no, I didn't have to run away (though I ended things with only 3% hull left).
How many engagements would you be willing to lose in your Krait? I could take my Viper in thousands and lose every time and still not care because the rebuy is so low (not that I typically need to rebuy). That same Viper, has no problems in a Conflict Zone (so it can be used for ranking up, Conflict CG's, etc.)
I'd say that if I can achieve my goals of protecting other commanders in some system, while within a small ship, then it is much more efficient than in a medium or large. Also, because the costs are so extremely low, the barrier to entry is also so extremely low and zoomies are so extremely high, it far surpasses medium and large ship combat, for me.
I could lose my krait plenty of times, it is just as much of a throw away ship to me as a viper. You can protect others in a small ship, but a large or medium ship can do it better. Cost should not be the primary factor in a ship's performance.
Another user stated this above:
Medium and large ships are better at a lot of things - they should be better at something, with that price tag - but small ships have their uses where neither cargo capacity nor raw firepower is required
I'm not sure why you wouldn't want a more specialized viper. The reason combat is talked about so many times on this forum, is because combat is a primary factor in the game, EVERY ship comes with weapons mounted on it. More specialized strike craft would be an amazing thing, why wouldn't you want that? I don't even understand it.