I don't have any stats to back it up, but I did watch ND every Saturday the past two years and was always impressed by Carlson. He seems to have good hands and is a big guy. I remember him having a huge game against Michigan State a few years ago (I know, its only one game). Anyway, this could just be a biased ND fan talking.
One thing is for sure, the Bills shouldn't have to worry about character issues with this guy (or most graduates from ND).