Overall, I would say most have been roughly average. Casilla, Carroll, and Span have all been good at their respective positions. Willingham has been not so good in left and Doumit questionable in right. This is all what we expected though.

Valencia I think needs more time before we determine if last year's -18/-13/-6 is his talent level or if it was an off year. All three liked him in 2010 (+3/+5/+6), so there's some hope there.

Mauer's numbers at catcher are almost entirely because of stolen bases. If one or two runners were instead thrown out, I think he would be rated as average.

Finally, I think it bears mentioning that all three divorce position from how good the player is at the position. Mostly, this is okay. However, it is an issue with B-R's 'dWAR' rating, which I do not like. It makes it easy to forget that a -10 shortstop (say, Plouffe) is equivalent to a +5 corner outfielder. Not exactly equal, but pretty close in fielding value.