So, I stopped watching this at the end of season 2. This show is a mixed bag, really.
Here are some pros and cons:
Pros: 1. They chose good actors for the parts.
2. The characters(for the most part) feel like themselves, and comic book lovers will be able to recognize them(save for a few awful choices)
3. The first season has a good story.
4. Maxwell Lord is a great villain/antihero(unfortunately that's where their good villains end.)
5. The Martian Manhunter, J'onn Jonzz, is played pretty well and gets good characterization(but unfortunately they basically jobbed him in most every fight)
Cons
1. The villains are at best ripoffs of Superman villains(Kara's aunt and uncle are basically 2 cent ripoffs of Zod), and at worst, strawman characatures of political opinions the writers dislike.
3. The show cannot escape from it's blatant political posturing, creating horribly bad stories to vent the political frustration of the writers.
4. If that wasn't bad enough, the political issues aren't even explored in any depth, having the substance of the average Twitter comment. They should have presented both sides evenly, and let the audience decide. Instead, they become very sophomoric in their presentation.
5. Kara is a bit of a Mary Sue, showcased by her fight with Superman. The villains and threat scale of her opponents pale in comparison with the things Superman has fought and defeated on a regular basis, and we're supposed to think that she's grown enough to defeat him one on one?
Kara was not developed enough as a character for us to feel like she deserved such a powerful feat.
All in all, I give it a 5.5 out of 10. It's a pretty average show, not because of the characters, but because of the story the show writers chose to create with them.