He has walked out of Arkansas practices and talks tons of trash (even to his own teammates in practice). He constantly tries to fit passes between two and three defenders because he has too much confidence in his arm. His short and medium accuracy is a big cause for concern.
He earned six unsportsmanlike conduct penalties in college (unheard of for a QB), was thrown out of a high school game for taunting an injured defensive lineman and supposedly failed a drug test at Michigan. His marijuana use is legendary in Texarkana. He got busted for distribution his junior year of HS and his dad paid his way out.
He can throw the ball a mile, though...but so could Jeff George and JaMarcus Russell.