Some of you have spoilt it for those of us who haven't finished. I know I watched it back then but I don't remember a lot of it. I don't really care though 
Watching the show from a modern pov, A LOT of things they (all of them) said which flew over my head before, now made me so uncomfortable and some even pissed me off (eg: Good hair? wtf??) but I still see it as what it is: done when those things weren't seen as they are now.
I like William, he's really funny but I lol and smh at the same time at a lot of his lines because that shit wouldn't fly now. There's no way he'd get those lines in this day and age.
I also really like Toni and took her the same way I did William: not so seriously most of the time.
I like Maya on her own, though not keen on her reverse snobbery. I could take or leave her storyline with Darnell. It was a good one still, I agree. Great character development.
Spoiler (?): They changed her love interests twice, poor her or shall I say, go her? Darnell was played by 2 actors and Toni's brother was also played by two actors.
I like Joan but her constant drama and whining about relationships/marriage, etc drains me. (Same way I felt about Friends. Watched it again for the umpteenth time and the whinging about boyfriends/girlfriends, dates, valentine's, etc just does my head in).
I thought Lynn's character was interesting in the beginning and I really liked her but at some point, I agree it felt there wasn't much else of substance they gave her to do. I also note Lynn bore the brunt of the mixed race jokes when the actor who played Joan (Tracee Ellis Ross) is also mixed race. May have just been me but there seemed to be a bit of an awkwardness with Joan (or Tracee herself?) each time it happened. I noticed Joan never really teased Lynn in that way herself so they either didn't give Tracee those lines or she refused them?