I think 6 foot 10 inch Al Horford, who is a great defensive player, a very strong post scorer, good shooter from mid range and an excellent passer is a more valuable player than Deron Williams.
Huh.
All the offensive skills you listed are irrelevant since Deron is dominant on that end of the floor and Horford is not.
And yeah, Horford is a decent passer....Deron is one of the best passers the NBA has seen in recent years, along with Nash, CP3 and Rondo.
The gap between Deron/Horford defensively is miniscule compared to the gap offensively.