The reason i take Smith over Okafor is not just about stats (although stats dont lie Funk), is for the mere fact that:
Smith is getting better and better each year.
Okafor seems to be platueing, and while he'll consistantly give you a 14/10 season, Smith on the other hand will be giving you 20+/9+ now and maybe even more later down the line... to go along with his 3 blocks per game.
this ties into his IQ, while not as high as Okafor's, Smith's is definitely getting better and he will learn and adapt over the course of his career, and get smarter.
Smith is young and athletic... he's very healthy, hasnt had any big injuries and doesnt seem to be an injury threat.
Okafor on the other hand isnt as robust and has missed alot of games over his career.
he isnt as athletic and looks like he may get run down sooner rather than later.
every player is after a long term deal (5 years or more)... i'd feel alot better giving a lengthy contract to smith as opposed to okafor.
in the long run, smith is the smarter choice, IMO.