Here's an excerpt from the Insider Piece:

For most insiders polled, the choke point for just how good Yu Darvish would be occurred somewhere between Garza and Greinke, although a majority still preferred the Japanese import. It's important to note that even the reservations about Darvish had little to do with his talent, and everything to do with the adjustments he'll need to make, from working on shorter rest than he had in Japan, to dealing with far more dangerous hitters, to a new strike zone. Still, reports from professional evaluators, and the ultimate price paid tells you that he was the best pitcher available this winter, and while he was priced beyond many team's reach, the industry generally believes he will be worth the heavy price tag.