Zeta Finn or CLS?

I'd go with zFinn. Reason being is he gives you a squad that can 6/6 any CM that Resistance can take part in. Resistance can beat any team in GW with some TM preloaded. They also score 2mil+ easily with just the one zeta for HAAT P4 or P2.

Just an all around good squad.

I dont have luke so i cant say for sure...but my last 3 went on finn and r2 and im very pleased!

Finn. I don't have either of them(well Finn is 5* g8), but still - Finn. Far better than any of CLS' zetas, if we are to compare them. CLS can wait a bit.

When you lose the Han battle (if Han hits any rebels apart from CLS), CLS gains 20% TM meaning he will go first regardless of how well their other chars are modded. He'll start with his buff immunity special, give everyone 10% TM and basically you can outspeed them.

It makes a massive difference in arena, but apart from arena; it's just a mediocre zeta imo.

For arena Luke, for raids Finn.

I would say it depends on if you're struggling to stay in the top 20 in the arena. If you're on a shard or have fast enough mods that top 20 in the arena is no problem for you, put off zeta'ing Luke and do Finn.

If you still need help in arena, zeta Luke.

Finn. Good in many areas of the game. Probably the most OP zeta there is.

id say luke, better for arena, can solo the entire p1, good on p2/p4 with rebels (or clones, idk about other compositions) and good on p3 with various teams

Finn was my first zeta and I have never regretted it. His zeta makes Resistance a powerhouse against most game modes. I mean, I haven't tried them out in the tank raid yet but that's only because I don't have Poe's speed high enough. However, I've gone from 8/10 GW to over 50 GW in just the month, month and half that I've had the zeta and that includes node 12 teams with CLS. They also walk through battles in TB easily. So Finn is my recommendation but I also don't have CLS so I can't make an opinion on his zeta.

Everything people said above about finn, definitely finn unless you already auto GW, you dont care about TB and raids and you are 500 in arena