I was spoiled for some of the more fangirl-squeeee stuff, like Sherlock in the sheet and I'd heard there was some wank about why Irene had to lose instead of winning as she did in the original story.
I don't think she "lost" per se. She GOT to Sherlock, whether John (or the fangirls) can stand to believe it or not. She clearly was seen as his equal and held her own throughout. The ending took me totally by surprise and that doesn't happen often.
I still think there's a certain amount of fanservice going on and that Moffat is telling instead of just showing. I think it would be simple enough to have Sherlock humiliate the girlfriend without making her spell out "I hope you'll be happy together." I thought the giggling at Buckingham palace was just out of character. Chuckling yes, giggling like children? No. Not Sherlock anyway. Maybe John out of nerves, but not Sherlock.
I LOVE Lestrade and I wish Donovan had been there, because I totally hate!sex ship Sherlock and Donovan and I would have loved to see Donovan and Irene have a little snark-fest.
I wasn't crazy about having Sherlock be too cuddly and cute with Mrs. Hudson. It felt over-done and again OOC, compared to how he was in the first three episodes. I LOVED Mark Gatiss' Mycroft so much. Sorry Stephen Fry. At this point Fry is always Fry. That's fine if it's a goofy thing like the Ritchie movie, but Gatiss IS Mycroft. (It probably helps to be able to write his own dialogue.) He was pitch perfect. He and Cumberbatch are amazing together. It's probably a squick for some of you, but there was a bit of Mycroft/Sherlock fic when the first episodes came out and it makes even more sense now.