Fl4k at 3% just says everything about the short end of the stick he received.
Zane definitely has the best skill tree. Not only is it really powerful, the power it has builds from synergies, whilst encouraging new ways to play the class. MNTIS is the best action skill in the game hands down - and does alot more than being an anointment/Kill Skill proccer - it can apply debuffs, drag enemies in, freeze, and if played right, even be incredibly powerful on its own. It also doesn’t suffer from poor design stemming from Mayhem scaling BS or whatever. I do think it is a little too strong right now, and Commitment is a way too much of a win button - but GB should fix that down the road.
Amara’s is currently 2nd best by default. Amara is really very strong, and her new skill tree reflects lot of the character’s strength - easy damage, great survivability etc. But I feel all of her skilltrees lack something to tie the whole deal - in other words, synergy. Her purple tree does alot, but not synergistically, lacking cohesiveness and identity. Maybe once they fix Infusion/FE to actually work properly the tree will find its feet. Also, Mayhem scaling on skills which shouldn’t get it (Unweave the Rainbow, Shooting Star) is just horrible design.
For Moze, I think as an Iron Bear tree it is great. But that seems to go against the design of Iron Cub, which was obviously to have Iron Cub as a support to Moze herself. So to be the tree with the least focus on Moze personal DPS when she is able to play on the field 24/7 is just odd. Also, the actual design of the DPS skills is just boring an uninspired, and doesn’t really build from potential synergies of dealing incendiary damage/iron cub. And Big Surplus 1) being active when AS is on cooldown 2) receiving Mayhem scaling just tells you all.
Uh, where do I start with Fl4k. Positives wise, it is a amazing pet tree - easily increasing their damage by many times. And uh, Fuzzy Math is a great skill - albeit still worse than 1 point in salvation. The rest of the skill tree is just really mediocre. Neglecting to give a single skill which buffs Fl4k’s own DPS is just really odd - no other skill tree in BL2, TPS and 3 actually has that problem. And buffing shields just goes against Take This - given the best shields with pet generally involve breaking them consistently or keeping them down. While Fuzzy Math is great, it is the only incentive to wade through 4 tiers of mediocrity, and Capacitance and Keep Them Safe have got to be some of the worse capstones/tier fives. Even the skills with potential, like Not Even a Challenge and Monkey Do just generally fall flat from poor design.