Sherlock Holmes: the TV show v. the books

In my post about A Study in Scarlet, I said I'd create a list comparing the TV series Sherlock to the books and short stories.  I'm doing this for my own entertainment, as this blog has become a book journal of sorts for me.  I actually finished all three seasons of the show two days ago!  I haven't watched the 2013 Christmas special; it isn't on Netflix and I haven't tried searching for it elsewhere, but I will get around to that eventually.
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Things I like about Sherlock:

1. It's set in the 21st-century.  I don't think using 19th-century England as the setting for the TV series would have cast as wide a viewership as it did, or lasted more than two or three seasons.  It is now going on season 4, and, in my opinion, it is still a very strong show with a story line that could keep the show going for many more seasons.
2. The friendship between Holmes and Watson is as I had imagined in the book.  Watson is Holmes' moral compass and he becomes the one person Holmes loves.  There are no ulterior motives behind his interactions with Watson, which is a rare thing for Holmes.
3. That Watson plays a very important role.  They could have easily made him a sidekick that stays in the background, but I'm so glad they didn't do that.  He has a very important role in the show.  Holmes is, of course, the front man, but Watson isn't too far behind.
4. Watson's blog in the show as the equivalent of his journal in the books.
5. ALL the parallels between the books and the show.  It's rarely an exact depiction of the scene from the book, but the clever way in which they turn something that happens in the book to fit the modern setting is so entertaining.  My favorite examples:
• Season 1, Episode 1: the villain's use of the two pills like they did in the story.
• Season 2, Episode 1: Irene Adler.  I actually liked her character in the book better, but they put an interesting twist on the character in the show.  I also liked that she was "the woman" in both the show and story.  
• Season 2, Episode 2: the main deal is still between two friends.  And the fear surrounding the hound is similar.  The modern adaptation of this story was done well.
6. Lestrade and Mrs. Hudson.  They are the perfect 21st-century versions of the characters in the books.  They did that beautifully.

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The one thing I don't like about Sherlock: Two years between each season!  What?!  Tooooooo long, especially now that I'm caught up with all three seasons.
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Things that are done better in the books:

1. The cocaine habit in the books versus nicotine in the show.  I understand why they don't have him use cocaine in the TV show, but that was a part of his character that I liked.  It was his one vice that he himself understood to be a vice.  He has an endless list of flaws according to the other characters in the stories, but he doesn't see those as flaws.  Rather, the things that others see as his deficiencies, he actually sees having those traits as a weakness of character.  
2. In the first season of the show, Holmes is portrayed as more obnoxious compared to the image I have of him from the books.  However, as the seasons progressed, he became less rude and started to mirror the picture I have created of Sherlock Holmes.

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This list is much shorter than I had thought it would be.  If I remember anything else, I'll add it later :)