I was apprehensive about this episode back when I first heard about it, and didn't feel much better due to not really liking the way that Before the Storm's main story played out and some of the decisions the developers made throughout. I was actually really pleasantly surprised, though, at how much I enjoyed this Bonus episode, and very glad that it fit in fairly well with the original game. Bringing back the original VAs was a nice touch, though I think all involved did a pretty great job.
The events taking place in such a small time frame does seem a bit contrived for maximum tragedy, but I felt like it was a pretty believable chain of events. They mentioned in the original game that Max's family moved shortly after the accident, and when you see the morning of the crash back in Life is Strange, the girls certainly aren't acting as though one of them is leaving town. I felt like it was a pretty smartly written addition to the overall story, and a much better way to leave things than BtS episode 3. That post-credits stinger was a real dick move!
So, yeah. It was a good ending. I'm happy with it, and actually glad that this is hopefully the last we'll really see of these characters. I'm a big fan of letting stories end in the right place, and this one certainly feels like it's wrapped up. I do look forward to whatever they're doing for Season 2, though.