Spoilers if you haven't watched any of it.
I've watched it all and I'm in the last season, but it's just got too many flaws. Jimmy is just a turd/used car salesman/gutter lawyer, that's okay, but there's no character arc, there doesn't always have to be one, but he's just the sleaze he is in BB.
There's no chemistry between him and Kim, it's like they're cousins or just acquaintances, it just doesn't work as a believable couple on any level. The whole 'my brother's a genesis lawyer, but a nut' seems so fake it doesn't add any real value. He is so disappointed in Jimmy and then kills himself.
The worst part is it's so unnecessary. (A lot like Book of Fett) He's just not a worthy character in BB to have a back story, I think Mike's back story would have been potentially more engaging.
I'll stay to the end to see how it plays out, mainly to see how they get rid of Kim, but I couldn't watch it again.
Just my 2 cents.