Finished over the weekend, episodes 6 & 8 are the best IMO, great pacing and tension in those. Episode 7 is kind of out of left field and seemed mainly just a setup for the mechanism to resolve the season. Which speaking of, liked the last episode (9) a lot as well even if things were tied up a little too neatly. It's almost as if they were possibly thinking there wouldn't be another season although the creators have said they want to do 4 seasons total. I'd give it an 8.5 out of 10.
Only complaints would be I found the sister and will's older brother's plotline pretty boring and didn't contribute much to the overall story, especially compared to the role they played in the 1st season. Same with Mad Max's older brother who seemed extraneous to everything. They also expanded the big haired boyfriend's role a lot which I think was a plus (especially when they paired him with Dustin), I found him to be one of my favorite characters this season.