I loved the show. Most of the time.
I won't lie and say that it'll ever win over a majority of fans, because it's not technically a good series. Despite all its faults, it's a show I've enjoyed quite a bit since the very first episode. I think a great deal of my liking towards the show is related to the cast and the effort the show gives off to me. Yes, it does have flaws, but it feels like such a genuine effort was being placed in the show despite its major show runners being inconsistent, leaving what seems to be a lot of the traditional second string people to pick up the slack.
The cast isn't the best that Sentai has to offer, by any stretch of the imagination, but there are a few moments when everyone comes together nicely. Yudai Chiba and Rika Sato struck me as the strongest members of the cast, they were pretty much always giving out a performance that matched whatever their character was going through in any given episode. I definitely would have preferred a stronger cast all around, but if I had to pick, I am glad that my two favorite characters, the Skyick tribe members, were the ones with decent cast members behind them.
Arata in general is without a doubt my favorite red in all of Sentai. We often see simple poorly done imitations of past reds or the introduction of a new kind of red that doesn't quite hit its mark, but Arata was neither. Shinkenger and Goseiger had rather unique reds, neither character's overall type had been done before; two years in a row of new things was great. That said, I much prefer Arata's character type to Takeru. Arata is...yeah, essentially a magical girl lead in a Sentai red's clothes. He's aloof while still managing to be a caring character, and this is the sort of character Yudai Chiba knocks it out of the park with – he's great in the role.
What impressed me the most about Arata and Yudai Chiba was their ability to change directions at the snap of the fingers. Arata is presented as the calm, quiet, and reserved character throughout most of the series, but it's hiding a fierce inner strength. When Arata goes into battles with desperation you can't help but admire just how different he seems from the way he usually acts. I think this is because the character and actor are a perfect melding of two strengths. You've got a pretty good actor for Arata in Chiba, but you've got an even better character in Arata. With Arata we're presented seemingly carefree leader, but when those situations arrive that test him or his friends, the viewer should be able to see just how far he's able to go to protect the people he cares about.
On top of all that, Yasuhiro Takeuchi makes a fantastic suit actor for the character of Arata. His colorful and energetic movements really bring the character to life in battle and give him a sense of oneness with the character out of suit. I would love to see Takeuchi as a read again if he was ever given the chance to do a more colorful lead character. I often found that Goseiger's action was a lot of fun to watch, unique and creative, it was never dull.
The cards did bother me, they never seemed to belong in the show. It's a Bandai thing though, can't really do much about that. Despite the cards, Goseiger seemed to work very well visually. I loved the Headder gimmick more than I can say, it's much more interesting than just switching out one mech for a different one. The weapons are some of the best I've seen in Sentai in quite a long while, and Gosei Great itself is my favorite main robot combination in Sentai.
And of course you've got Brajira to tie the show together. The moment he appeared in the second arc, you had to know he was going to be the biggest threat throughout the show and, at least to me, that made me pay more attention to his actions. A shame that happened in the second arc since it is the weakest of the show and admittedly the hardest part of it for me to rewatch, but it's one of those things that made it interesting in the worst of times. We had this very conniving character who worked against everyone and everything and made for an excellent villain. I would say it's a shame he wasn't the main focus throughout the show, but the build up makes him all the better, and the changing enemies thing was pretty awesome as well.