I don't hate Kiva - I actually enjoyed watching it, which is more than can be said for Faiz. I liked Wataru, though his character development got a bit schizophrenic towards the end. The suits were great, especially Kiva's basic one (Emperor form not so much, but it wasn't bad), and the fangires were cool too, even if at times it was tricky to tell what animal they were supposed to be representing.
But it had issues. The main thing I dislike about it is Otoya - I get what they were trying to do with him, and I see why some people like him, but to me he just came across as insufferable and annoying. But I liked Tendou from Kabuto, who in some ways is a very similar character, so I don't know. He's also a complete douchebag for leaving Yuri for the Queen lady without even talking to her about it at all. Another thing I didn't like is after they established that Fangires do have souls, I felt kind of uncomfortable when they were killed, ESPECIALLY the Grizzly fangire who, if I remember right, didn't even kill anyone. Sure, most of them were amoral murderers, but still.
Another thing that bugged me was the massive sexism in having the IXA using women both get displaced by men, like the women were just borrowing the power from the men. Normally I'm not that bothered by the lack of female riders (though I would much like there to be more of them in future), but when it is dealt with like this it feels really sexist. Especially when Nago is fucking BLIND and he's still the one to use IXA rather than Megumi.
Finally the amount of things that made no frigging sense, for example Kiva's bird form was just stupid and came out of nowhere, and massive overuse of characters just randomly meeting in the street. It got to the point where it felt like characters were thinking "ok so I need to talk to her, maybe if I just walk around randomly we'll bump in to each other", and then it consistently worked. Again comparing it to Kabuto, at least in that show it was kinda explained by Tendou's magical haxxor powers, and they made a running joke of it. In kiva it was just sort of there, and both the plot and the characters were relying on it way too much.
But as I said, despite that I did gain enjoyment from the show. Also I really liked the ending, when they all ran out to fight the Neo-Fangires I was like "YEAH!"
.
EDIT: Also Mio was just boring.