I saw the Sherlock season two opener last night, and was impressed. Previously I've only seen the last half hour of season one, which wasn't really much to go on though it looked like a decent show.
Watching it, I wasn't clear on whether the ending was meant to be a fantasy. I suppose since Sherlock couldn't have known the details of how Mycroft was supposed to have disposed of her, it couldn't have been.
However, it was a great episode by the standards of any TV series. I like the longer format and the amount of incident they pack in. An equivalent HBO series would've made that a 3-4 episode arc with a lot of establishing filler.
The sly humour of the detection gimmicks is great as well. Like the two bags under Watson's eyes tagged "Night Out" and "With Stamford" 🙂