What's the skinny on fat asparagus? I had always heard that pencil thin asparagus is the best, and that has always been what I look for. But now I've heard from a few (what I would consider reliable) sources that skinny isn't better when choosing asparagus. My local grocery tends to get really fat (stems easily an inch in diameter) asparagus that otherwise looks great (nice color, tight tips, no wrinkling). I've always avoided this asparagus even though I love roasted fresh asparagus, because I've expected it to be woody. Is that the case?

I've never peeled asparagus, I've just snapped off the ends at the "break" point. If the consensus is that this fat asparagus is worth trying, should I peel it before roasting?
Martha's Vinyard Magazine suggests that the diamater of the stalks is not directly related to their age as one might suspect:


  Some might assume thinner spears are younger and therefore more
  tender. The diameter, however, has more to do with the age of the
  plant itself and the particular asparagus variety.


They go on to cite Cook's Illustrated, saying:


  [T]hin and
  thick spears as equally sweet, nutty, and grassy, but ...
  thicker spears have a slightly better, more tender texture. The reason
  is that the fiber is somewhat more concentrated in thinner spears.


You can peel asparagus if you choose to.   Personally, I peel the base of thicker stalks.  Mark Bittman recommends peeling from just under the flowers to the base of the stalk on the thicker stalks.

Thinner stalks may be easier to saute or grill, and thicker ones more suited to steaming, poaching, and so on, but this is more related to the time it takes them to cook through.

See also: 


Mark Bittman writing in the New York Times
Better Homes and Gardens
Martha's Vinyard Magazine