I have multiple copies of each Dirk Gently book, including soft covers, hard covers, first editions, and signed copies. This show kept Dirk pretty darn close to the true spirit of the originals. The stories are reminiscent of something Adams may have written in the early 2010's.
Mangan is the perfect casting for Dirk, and plays him naturally. MacDuff is a bit more bland than the novels, but is played well by Boyd.
It is a shame that there are so many people that don't appreciate how well done this show as, from the perfectly themed and timed musical cues, to the cinematography itself.
Any true DNA fan prefers this adaptation to the horrid, new atrocity playing on TV.