Just finished. Still love the characters but overall was very underwhelmed with the choices.
I think the problem, and the reason the show slowly became something that wasn't as good as the first two seasons, is that it became overly serialized. They peaked with Moriarty and the Reichenbach Fall, and then I guess they felt like they had to keep making the macro story bigger and deeper at the expense of the micro stories of each episode.
I think we all would have been much happier if after Moriarty they didn't try to top themselves each season. There was no need. It would have been fine if the characters slowly moved forward in their personal story lines over time while we watched really interesting individual cases play out. Maybe they thought it would be repetitive to watch a bunch of smaller stories like "The Woman in Pink" play out with no longer arc payoff, but if so I disagree.
It really seems like after the first couple seasons the writers completely lost interest in writing really good self-contained mysteries. We could have gone multiple more seasons just watching Sherlock and Watson solve complex crimes and they still could have squeezed in some of the fan service that completely took over last season. Episode two with the serial killing philanthropist could be a great example of what I'm talking about if it wasn't so wrapped up in the bigger story of Mary and all the drama from episode one, and the drama to come in episode three.
I agree with whoever said that it's a shame this is the best story we could get after such a long wait, while simultaneously agreeing with the person who said it's still a solid and mostly satisfying wrap-up, if it's really the end.
Just wish they would have been less ambitious and would have just given us some more really good, entertaining mysteries before expanding the back story so far that it basically had to be wrapped up.