One of the main concerns about Rubio was if his body would hold up to an NBA schedule. He had injury problems playing twice a week in Europe. It's too bad, but for as hyped as he's been, he's still just a 15 PER player who shoots 36% from the field. For comparison, as bad as Felton's been, he's at least shooting 38%, and has a lower TO% than Rubio. I'm not saying Felton is at all at Rubio's level (Ray has a PER of 11, for chrissakes), but Rubio's hype has been a bit ridiculous when you actually look at his advanced statistics. Rubio's WS/48 is fairly pedestrian at .090. For example, Felton had a better number than that his last 3 seasons prior to this one, and Ridnour's .107 this year says Minnesota may not be in as much trouble as people would think.
For a rookie, new to the NBA game, I think he's doing good. His 8 assts a night is the most telling stat. I don't think he's going to be a superstar. But, he'll be the type of PG that could lead the league in assists every year.