I'm sure spoilers will appear in this post, so tread carefully if you haven't watched it.
I tuned in maybe five minutes late, so I'm not certain what was going on in the prison, but I'm digging it so far. Sherlock building his disguise at the restaurant was excellent, and the mustache jokes crack me up. Unfortunately, for some reason, my local feed has these hitches happening every three seconds, and it's driving me up the wall.
EDIT: So I just got to the end, and I loved everything about this episode. My only regret is that I don't have a DVR or anything to watch it again. I think they made Sherlock more human this time around, and I think it made it better. I also loved that he never explained how he survived the fall. I really hope that every episode this series has a different, equally implausible explanation. It's not a comedy, but that doesn't mean it can't have a running gag.