I liked it.
I liked the nod to ACD canon with Mycroft's being hugely overweight and still the only person smarter then Sherlock. I liked that Mycroft and John were so angry at Sherlock's using drugs and of course I loved that John truly sees Sherlock and knows he needs companionship and that he shouldn't be alone. I especially liked that John made sure to point out that the Sherlock Holmes he wrote about was not his true persona, that he was so much more than that. Nice :)
Mary and Molly both continued to be cool and to understand the Johnlock friendship better than anyone else and I like that the show had Moriarty being Sherlock's greatest fear. But what about Sebastian Moran? Can't wait for Season 4 to begin :)