I'm a big fan of the original stories, too, and it was such a pleasure to see characters that weren't necessarily exact adaptions, but got the feel of the relationship the two shared. To be fair, it's a bit more superficial in the books, but, there was always the undercurrent of partners on an adventure.
Yeah, I knew exactly who Ronald Adair was and was not surprised what happened. (Though, in the books, it was Moran)
It really is missing in a whole lot of adaptions and it's such a shame because it's what I love about the canon Holmes.
I started watching because it was a Sherlock Holmes adaptation and I'm a sucker for those. I stayed because it clicked with me, I really liked how Watson and Holmes clicked. And then I just loved how they sprinkled in so much fun stuff. Ms Hudson. Clyde. Everyone. Bell and Gregson. Kitty. The Nose (was that the name?) It just worked so well and I'm going to miss it. I have discovered it is eminently rewatchable.