By the achieved numbers Rondo wins. Rondo had a better PER by a significant margin. Better assists, steals, rebounds, and points allowed per 100 possessions. Smart has the better TS% by a significant margin, has only played 37 games, and is injured.
By my eyes as a rookie, Rondo. As a pure PG, Smart will never be close to Rondo and if Smart doesn't get past being a 3 and D combo guard then he's not going to surpass Rondo's accomplishments. However, he's shown enough to think he might and he's been able to improve significantly in a major facet of the game.