The voices are really good. Sherlock's voice actor has a great baritone and his rant about the airplane near the end was perfect, which couldn't have been easy given the number of words and speed he had to match. He doesn't play the sarcasm as well, though, and tends to put more emotion into things than Cumberbatch originally did. But it makes his interactions with Mrs. Hudson a little sweeter. John's voice has great comedic timing, I liked him last series too. Moriarty's voice is just...he sounds like a ten-year old boy and that sort of works for the character and Andrew Scott's interpretation of it, but when you get to Moriarty's more serious, quiet moments, it doesn't work as well. Though the glee with which he delivered the 'I'll make you into shoes' line made me laugh. Irene's voice was spot on - really sexy and well delivered. Mrs. Hudson sounds a little silly, Lestrade sounds like Rupert Graves speaking French and Mycroft sounds a little young.
Some translation notes:
-Instead of Mrs. Hudson calling John and Sherlock 'boys', she calls them 'les enfants' (children). I think that's sweet.
-John's line about baby names is changed to - 'if you're looking for names for the baby', as though it had already been conceived and was inevitable.
-The punny titles of John's blog didn't really work, but they did a good job with the [spoilers!]'I am Sherlocked' thing. The text on her phone read 'Je Suis Locké', which works well enough in Quebecois French where they throw in a lot of English. The first three squares of the password area said 'SIM' in them, but I don't quite know what that means. Maybe it refers to a SIM card?
-I like how they say Irene in French (Ee-ren), but I don't understand why Mycroft is not then Meecroft. Hamish becomes 'ameesh'. And they've finally decided on a universal pronunciation of 'Holmes'. It was all over the map last series.
One thing I realized while watching this again: [more spoilers!]On one of the entries to John's blog that the BBC set up, Sherlock doesn't recognize a Bond reference and John declares that a marathon is in order. Then on Sherlock's fake forum, he posts while he's watching (and enjoying somewhat) said marathon. This is probably why he makes the connection between 007 and BondAir, a pop culture reference he normally wouldn't have gotten. Clever show. Clever.