Given the male lead (Caviezel) basically seems to give up on acting entirely in S3/4 (he's decent in S1, okay in S2 but it's steeply downhill from there), the entire emotional heft of the show ends up being on the supporting cast and minor characters. And they definitely have the strength to carry it, but normally they wouldn't have to.
I've watched the whole thing and I don't think it's worth struggling through. It does get good and has some of my favourite actors in it (not the lead lol), but I think it's got too many episodes which are just sort of dithering and Caviezel becomes less and less compelling. Accounts from people who were making the show rather suggest this is because he was in the process of essentially vanishing up his own ass, ego-wise. His behaviour actually got so bad that he eventually got banned from filming certain kinds of scene which a lead normally would do (particularly car-related ones). It's a pity because Emerson, Henson, Shahi, Acker and Chapman do great work here and seem to be having a good time too.
It's a bit like the X-Files too in that sometimes the filler episodes are better than the mythos ones, and sometimes it just sucks.
