I haven't finished Kabuto yet, but I'm about halfway through, and overall it's really good. Souji Tendou is a good protagonist, and even though he's arrogant, it's never done in an annoying or forced in way, and Arata Kagami acts as a nice, more down to earth counterbalance in arc 2, and their dynamic is really nice. Apart from the main 2 riders, Sou and Shun are interesting side characters, first as 2 different users of TheBee and then the 2 Hopper Riders, Daisuke has a minor subplot relating to his companion Gon and her past which is a nice bit of arc 1, and Tsurugi is a tragic hero, but does become much more likeable as the story continues on. Souji Kusakabe is also an interesting villain near the end, however, that's a spoiler.
The first half is somewhat slow, as it mainly establishes the characters, however arc 2 is amazing, and is relentless plot wise. There's some weird episodes in there, like a random one with a cooking battle between an order of good and evil chefs, but the more comedic moments are a pretty nice addition.
Overall, kabuto is really good. Interesting characters, and a good plot once it gets going. If you're into tokusatsu in general, action or just want a good sci fi drama, this is well worth a watch. The movie, God Speed Love, is also a standalone alternate timeline, so if you're into post-apocalypse and dystopian sci fi, that's worth a look too.