...at a good price, provided that you make one major alteration (see below). I ordered a large and and extra large in two different Dorfman Hat styles. The XL went full down on my head over the tops of my ears, and it was loose.  For appearance purposes and traditional fitting the Large is right for me.  I have a 23 1/2 inch head size. So I would say to think of Dorfman sizing as about a half inch greater than the Amazon chart.  You will see that nearly everyone giving a review concurs.

Now the alteration.  I soon found the hats unusable because the bendable brim was impossible to keep from crumpling up while wearing it, I would find myself having to reshape the brim several times when I wore it, even making best efforts not to brush against anything with the brim.  After a few years of retirement I took out a razor and sliced a few threads sewn into the seam holding the metal flexing rod, grabbed it with needle nose pliers, and clipped it in two.  Then I could pull it out and discard it.  The hats are great now, they somehow just took on a bend down near the front and the back, pretty much what I would have wanted.  Just make sure you make the cut in the threads where the metal loop is crimped together so you can pull it out easily.