I apologise for my title, I couldn't think of anything world shattering, so moving on ...
The performances were superb, lines delivered sharply, dialog flowed naturally, the chemistry between the relevant characters came across as natural.
I don't want to write any spoilers so:
E1, sharp and funny, I thought it was setting the tone for all that would follow.
E2, pace and humour fizzled out a little and I started to wonder if all the best bits were in E1.
E3, everything went dark, to say a number of scenes left me feeling very uncomfortable would be the understatement of the year, at one point I wasn't sure if I wanted to keep watching but was hooked by the amazing acting and script.
E4, twists, turns and alternate perspectives and a 10* rated ending.
I can only say that if you feel it's not worth sticking with in E2, keep going, your heading for a roller coaster of emotion.