I think most of us still aren't quite sure how to evaluate talent from Europe. If you look purely at the numbers you won't be impressed by many players overseas...
Take Mike Batiste for example, he just made first team all-euroleague and lead Panathinaikos to a title. His stat line for the season: 13ppg, 5.5rebs, 1 ast, 1steal. Forget 1st team all NBA, you won't even sniff a 3rd team honerable mention with a line like that over here.
Further - Batiste isn't even a starter; rather, Ian Vougioukas starts and sees roughly 5 minutes of action before being subbed out....If all that doesn't tell you how much the two leagues differ i don't know what would.
Regardless of how you slice it, Rubio still did have a down season - his shooting percentages were just plain bad. Seems like he doesn't quite fit alongside mainstay Juan Carlos Navarro. But still, he's never really been a "scorer," he's a faciliator and a teammate first.
This whole "i don't want to go to Minnesotta" thing has sullied his image and gives off the notion of a "me" guy, but i don't think that speaks for his play. Probably overhyped due to his success as a young teen, but he's still only 21 years old and is a seasoned professional, i would think he could come into the NBA and see a reasonable amount of success right away.