Right now, I don't know which film I'd vote for Best Picture...... but Colin Firth definitely has my vote for Best Actor. It would be fascinating to hear how he prepared for these speech patterns he had to perform.
My wife and I went to a taping of Inside The Actor's Studio when they were interviewing Colin Firth and he talks about it... I'm going to paraphrase, but he said it was more about TRYING to get the words out, rather than trying to copy a stutter. Like an actor in an emotional scene trying not to cry, ending up crying.
It's a great interview. Though, the taping is THREE hours, which they edit down, obviously, and THEN there's another bit after where the audience can ask questions, and that was another 40 minutes. My wife asked a question, I hope it's in the final edit.
I began watching it last night on YT. Fascinating interview.