I don't think it's terrible, but they've never managed to hit the highs of Season 1.
With Season 2, it's...good...but then things get weird. Not bad, necessarily, just...weird. I found it to be less "horrific" to be honest.
Season 3 had some viscerally disturbing moments, but also seemed to suffer from a more self-indulgent quality. Again, it's not bad per se, but it's just not what it could be.
Too early to tell with Season 4, although it's clear they're trying for the same kind of visually disturbing moments.
Really, I think the problem is that they don't understand what made the show take off in the first place. What made Season 1 really work so incredibly well. It wasn't the outlandish, fantastical aspects. Those were merely accents to an otherwise solid story about the real horrors that Americans visit upon each other regularly. The latex guy, the monsters in the attic, the school shooting, etc. All of these were terrifying more for their commonality, but as filtered through a prism of the fantastical.
By Season 2, though, the focus is on the prism, rather than the story itself, and so the genuine social commentary gets lost behind what was the accents of the show. Again, there's some really fine work done on the show, but I think they're focusing on the wrong aspect. This season, with its focus on the circus freak show, seems to veer even further in that direction. I'm sure we'll still see good stuff from the cast, fine performances, and disturbing moments, but it'll be those disturbing moments that are the real focus, rather than the humanity and its awfulness.
Alternatively, think about this: imagine if The Walking Dead ceased to focus on the survivors of the zombie holocaust and the human dramas visited upon them because of the circumstances surrounding them, and was just about a group of people wandering the land, killin' zombies, and occasionally being eaten themselves in gruesome ways. On paper it sounds awesome, but in practice, it'd become old hat pretty quickly. Kinda like playing non-stop Left 4 Dead/Left 4 Dead 2 in single player.