@Flatlyner adding to dieterbrock's post.
I watched all of Sanders games this year. He's got touch and can make most throws.
Where he completely lacks pro level skills is pocket awareness. He gets lost at times and makes silly decisions. He'll take sacks that make zero sense or hold onto the ball with short to intermediate options open. Some of this can be attributed to coaching, some of it is just a lack of natural instincts.
I'm a CU guy. IMO he's not a day one draft pick, possibly a 3rd round pick as a developmental guy.