Oh wow. Had no idea there was an earlier production of Dirk Gently. I've only seen the BBC-America one, which is magnificent.
As a lover of Douglas Adams (and a non-American), I adored the concept of Dirk Gently but felt the entries were some of the weakest material he'd ever released. There were so many great ideas but the characters were a confusing mess. The US adaption by contrast is possibly the most perfect blend or midpoint between of American and British humour I've ever seen, and one of the tightest time-travel stories that you can wish for without taking itself too seriously.
Looking forward to watching this previous series, I like Howard Overman and Matt Jone's other work.