I binged this in a weekend and overall I enjoyed it. There were many twists and turns, but there were also unlikely head scratching moments. I believe I enjoyed Darby more when she was younger and with Bill. I would not have minded more Joe Doe content, for sure. The setting in Iceland was interesting. I'd recommend it if you are looking for something new and you can suspend belief half of the time.
As an aside, I was bothered to distraction half the time over Darby's hair. Whoever was in charge of choosing her styles and continuity from one scene to the next missed the mark. When she was younger her, and Bill's hair for that matter, had terribly awful short bangs. Bill even had those same bangs later - what the what. Then Darby has plastered flat blonde hair that did not move and inch, ever. Finally she dyes it pink for a decent hairstyle for dinner, only to have that stylist inexplicably changed after she leaves the table. Later, it's wet, dry, parted then not, then shorter, then fluffed. I just could not stand it.