Jimmer is quicker, has longer wingspan, better jump shot, ranked as more athletic and pre draft, and was seen as a better defender, surprisingly. Delly was considered too slow, being ranked below Jimmer in lateral quickness. Scouts miss a lot that is obvious. USU coach knew better, i.e., that Delly had the goods to play both ends in the NBA.
Turns out, he is now held as a quality NBA defender.
http://www.nbadraft.net/players/jimmer-fredette
http://www.nbadraft.net/players/matthew-dellavedova
in addition, standing reach is the same, 8'1" vs 8'0.5"
Physcially the players are very comparable. The 2" that Delly has in height is offset by his poor reach and wingspan.
After time in the NBA, Delly has proven to be a stronger leader, much more active on defense, and a better ball handler.
i do believe Jimmer still has a chance to find a role in the NBA with some serious changes to his game.