You have to look at this as what it is, Sherlock absorbed into Japan's slightly rigid culture. It takes the core aspects of Holmes and gives it a Japanese twist. So as a westerner, some things stand out, like the reserved nature, which seems a bit muted by my standards, but every now and again there is an outpouring of raw emotion, which slips the social confines of Japanese culture. I have seen reviews that claim there is poor character development and bad acting, and that is very wrong. It does not have British "ham" or American "gratuitousness" These are reserved and compact performances but with added idiosyncracies by YÅ«ko Takeuchi in the titular role. A nice twist for me is how they play with the possibility of the much-loved character actually being on the autistic scale, with YÅ«ko Takeuchi reacting badly to loud noises in places. Like most things here, it is subtle and understated, but these are the little gems you can discover without the noise of bombast action.
My only negative from this show is the actual mysteries are a bit thin and obvious and can be seen a long way off, and while this makes Sherlock a more human and believable character, it is nice to have a very cryptic mystery unfold and be explained by the master of observation and deduction. There are lots of nods to Doyle's original tales, plus it is obviously aware of the BBC Sherlock series with many of its sensibilities. One unique aspect I really enjoyed was the fun they had with character's names, as Sherlock's medical room-mate and companion is named Wato, and to then give her, her title, Wato-san ;-)
I would love to see a second series.