I don't criticize, at least I try not to. The only way for people to improve without feeling like they're the worst writer in the world (I've had bad critics, I've been there) is to give constructive feedback. If I think something doesn't work, I'll explain why and make suggestions for improvement. Being that it is YOUR fic, you can choose whether or not you want to take my advice.

And really, the British-isms are expected if you're British. I shudder to think of me trying to write a Sherlock fiction without throwing out more Americanisms than dialog. Maybe if I have a British character one day, you can help me make him more realistic :D