Well I've finished RE6, and I have to say I enjoyed the game a lot. Not quite as good as RE4, but I liked it more than RE5. It is very action heavy, though, with a far larger melee system (seeing as there's a dedicated melee button and everything). I found Leon's Campaign to be the hardest by far, I had far more deaths during it. It also seemed to be the longest, but maybe that was just me dying so much. It also stands out as having some of the more memorable moments, and it has a whole horde of enemies that never even show up in Chris's or Jake's campaigns, which also makes it stand out. Chris and Jake share many of the same enemies (and even have sections of the game that are exactly the same), so it certainly has a bit of "been there, done that" feel between those two. The decision to give Leon his own enemies is quite interesting to me, and really makes his game stand out a lot from the other two characters.
And yes, Leon's campaign focuses a lot more on traditional "scary" things. More savage enemies that swarm you, darker locations (I don't recall a section ever taking place during the day in his campaign), and some more fantasical places that he ends up. Chris and Jake however are very action focused (and even some stealth in Jake's case), mostly battling gun-toting foes. Overall, I feel like splitting the story into three perspectivs hurt the narrative a bit, and the story feels a bit lacking to me. There's also plenty of larger-than-life moments that seem straight out of a michael bay movie, complete with things exploding for no reason (apparently every time a car flips it explodes in a giant fire ball, good to know).
Still, I must say I had a lot of fun with this game, despite its shortcomings. I can't say I regret playing it.