I bumped into Overeem in August in Atlanta as we were both transiting in the airport. I was surprised at how 'normal' he looked to me. I'm 5'11 and it didn't feel like he towered over me, and wasn't all that muscular - not as much as when he's in fighting shape.
He was nice enough to give me 5 minutes of his time - although I don't think he was too comfortable with some stranger saying "Hey Alistair!"
he certainly lost some size since his suspension for elevated testosterone. still massive for MMA standard.