1. His deep ball is horrific. Not the short and intermediate passes, but a few times a game, you need to take some shots 30+ yards down the field. Sure he can get the ball there, but the passes are often underthrown, forcing the WR to stop his pattern and come back to the ball.
2. He never throws the deep ball. He rarely throws any pass over 10 yards. Arm or not, you need to attempt those passes, if nothing more than to get the safeties off the line. Trent is hesitant at best and afraid at worst to throw anything other than a dumpoff/checkdown or a short pattern.