Absolutely fantastic. I will admit that I hesitated at first, but then I thought why not give it a try. Gloomy and eerie, but good at it. The music throughout the series is really well chosen; it fits perfectly well. The writing is also top notch, as is the acting. You can either have it in English sound or in German sound with English subtitles. Honestly I wasn't bothered at all with the English sound, so if that's your thing you will be able to enjoy the series just fine (maybe you'll also be slightly less distracted as opposed to reading subtitles). Personally I chose the German sound, as it felt more natural.

Honestly, give it a try. Might very well be the best series I've watched this year.

EDIT: Binged season 2 in a sitting. Just wow. This review doesn't do it justice. And the casting...I mean, I totally thought [spoiler]old Ulrich was the result of CGI or something.[/spoiler] Season 2 is best thing I've watched this year and last year included (ever?).