If I can be permitted to observe one of Breaking Bads very few flaws, it was that outside of Walt and occasionally Jessie, we saw very little of the any of the characters as independent agents. They pretty much all exist to be foils, or metaphorical warnings, or counterpoints, to Walt and his rise/fall to villainy. As such. I've never been too sure about the idea of spinning any of them off, because the really interesting characters in that mix are often either a) dead, or b) built on mystique anyway, and often both. Also, is it a world worth exploring? Breaking Bad is a deeply personal story, not a portrait of a wider world, which is, of course, ours to start with. But we have a spin off, based on a supporting character, and that is Better Call Saul, based around Saul Goodman, sleezebag lawyer extraordinaire.
Like many Breaking Bad characters we don't know that much about Saul Goodman. He has a series of cheesy adverts on bus shelters and TV, he dresses like the flashy, borderline legal con-man that he is. He has an office with the US constitution up on the wall behind his showy desk, and seems to alternate between ambulance chasing and work for New Mexico drug cartels. He's also fast-talking, slick, sharp tongued and a consistently bright presence on a show that is often deepy serious and self-important. So obviously, the spin-off series features absolutely none of that, staring with a breif look at Saul after the end of Breaking Bad before flashing back 6 years to well before it.
So meet Jimmy McGill. Jimmy is a lawyer, struggling to find clients and working out of a back room in a nail salon. His brother is - or was - a high flying, hot shot corporate lawyer who is now house-bound by a pathological aversion to electromagnetic radiation, and Jimmy is also campaigning against the blood-sucking law film his brother is a partner for, and he feels, is not being sufficiently supportive. Jimmy works day-rate cases down the local law courts, a natural showman with a flair for theatrics but locked to the small time circuit. Jimmy is working hard, in a world that won't cut him a break.
Even knowing that he will one day be Saul Goodman, I liked Jimmy. This is in part because so few other people seem to have time for him, and no-one wants to cut him a break. The air of the con-man sticks to him, the slick, shiny surface, the smooth patter, and wheras we, the audience see through that, few characters on the show are permitted to. If Walter White is a character starting in a state of grace that descends into darkness, Jimmy is a character reaching for the light, only to have it repeatedly snatched away from him.
Better Call Saul unpacks gently over it's initial run, building themes rather than plot, and letting information slowly leak out in an organic way. It rewards attention from the viewer, and doesn't offer much in the way of action, pyrotechnics or any of the sort of thing that many genre shows use to get you coming back every week. It's most powerful scene - easily a match for anything in Breaking Bad (which I should stop trying to compare it to but it's hard not to) - is just an old man, sitting in the darkness and baring the scars on his soul. It's second-best scene, towards the end of the series, is similarly structured, just a conversation draped in truths that still felt more real, and more gripping than any threat of the world was being destroyed.
I think Better Call Saul has made a smart move, picking a character we know very little about and giving him a back story totally fresh. I don't think you need any foreknowledge to watch and enjoy it either, although there are shout-outs and nods for those "in the know", and some welcome returning characters. But it stands perfectly well on it's own, telling it's own story and is all the better for it.