The I-16 is pretty difficult to get kills in, but for two reasons only: its low top speed, and its light guns package. Other than that, it's a fantastic, exceedingly nimble fighter. You can't force a fight, but if you play your cards right and lure an enemy to your altitude and speed, you have a decent chance at a kill.
Well, if your marksmanship is good, anyway. I think of it as a real man's fighter. Да здравствует Поликарпов!