Have to say that against my expectations I really enjoyed it too and am so pleased it's been renewed as, despite receiving a tepid response in Germany, was well received internationally, especially in my own country, England.
On a related note the series really reminds me of the BBC's Life on Mars/Ashes to Ashes series in terms of tone, style and narrative (minus the former's supernatural elements of course!).I wonder if the writers/producers of Deutschland 83 were inspired by those series as I understand that they were fairly popular in Germany.?
All that said though the series did occasionally strain plausibility with Martin battling Carlos the Jackal on a subway track (!) being particularly fantastical as well as his improbable ease in crossing the border back into the DDR near the end of the series.
Still, I loved it and that's a rare accolade from me given my general aversion to most modern telly these days (I prefer older shows generally).
Bring on Deutschland 86!