Taking players directly from S America to England will always be a risk due to the different technical aspects of the game. Here, in SA, the game is generally slower and less physical when compared to the premiership. I have not been impressed with Boca this year, but perhaps this is compounded by the inclusion of Riquelme who has been an absolute waste of space, although Roberto Palacio has caught my eye a few times (winger who can player either side). River Plate again have not been at their best this season, though i am a big fan of their stricker Farias. I have only watched San Lorenzo a coupple of times, and they do look good going forward, although they are not a team I really follow.
Here in Peru we are going through a dearth of talent in the National leagues. The quality is poor. I am very surprised that Farfan though has not been touted for the premiership as I think that he has all the requisites to succeed (power, pace, great upperbody strength, and a good mentality too), although Pizarro appears to be the one moving on (there were newspaper articles here a few months ago stating that Bayern were not renewing his contract due to his inappropriate lifestyle - drink).