Just finished this, very good.
Spoiler:
I love Alex

so I'm gutted that Prepon's leaving the show. The rest of the cast are super strong and even the very minor characters have shone (which is a great feat considering how many of them there are).
Satisfying finale though, even though you know she'll get in **** I was so glad Piper beat Pennsatucky's annoying ass

that said, she's a great character also.
The only gripe I have is that I reeeally don't buy the Daya/Bennett storyline. It was alright and more endearing when it was sweet and innocent but when she got pregnant it felt a bit... too soon? I also find Piper a bit grating at times, but that's probably because I generally get irked by goody-good types.

But yeah, it's a great cast and set of characters overall. I'd definitely recommend it to anyone.