Jek is amazing. I feel like in a few waves, we'll see an upgrade that puts him up there with the current powerhouse pilots.
He's basically a maverick that no other pilot can keep up with. Even against a TIE Defender, he'll win out due to having more actions with Push the Limit. R5-D8 will keep you topped off most games. Statistically, if you shed 1 stress with his ability and also use R5-D8 every turn, you'll repair more often than you take damage. But you can go many rounds without taking damage at all, so can feel free to gain a TL, or Boost with an Engine Upgrade.
