Such a good show but I feel it is a bit weaker than Season 3, but also sort of helplessly because has the bridge between BCS and BB becomes shorter and shorter, it will unavoidable lose some of the earlier characters or plots that made the first 3 seasons so good. In particular, I miss Charles and Howard. And other than a few earlier scenes, the lack of Nacho has also been missed. Mostly because I've mostly felt Nacho's drama is somewhat believable in the context of BB (e.g. even the appearance of Krazy-8 as a meek underling), whereas the new Gus and Mike drama feels some manufactured -- few times I felt things were, one, become a little too grandiose considering the scale of such things in BB (feeding the mythology of Gus a little too much), and, two, a little manufactured, as if afterwards I kept puzzling over whether or not the actions were even believable.
All that said, I'm of the opinion that BCS is still superior to BB, maybe not always in terms of acting (e.g. Walter certainly is on the same level as anything anywhere) but in terms of overall plot, theme, even presumption -- BB often tried too hard, I felt, believed it's own hype. BCS is really wonderfully grounded in that regard. And, even more broadly, the more I re-watch BB but also drama like The Sopranos, the more I feel I always overrated BB except for the acting. I really appreciate The Sopranos more every time I watch it, but for the same reason I really think BCS is the superior overall drama.
In some ways, maybe Vince Gilligan is somewhat liberated in BCS... BB became so big that there was this likely captive direction it had to taken on to constantly hype the mythology of Heisenberg, more than it likely deserved considering how often shit was actually a mess. With Jimmy/Saul, and also less hype toward BCS in general, I think maybe his vision with the directors has been liberated a bit, and they're able to 'check their own bullshit' a little more often. BCS reminds me most maybe of the original pilot, maybe much of season one, and being able to keep it a little more humble and vulnerable the entire ride.
Just my two cents haha I still love both either way. And I don't do much other than watch organized crime drama or narco novelas lol ain't not broadly informed critic by any stretch and biased to the genre.