Wormdrive saws, historically, are a West Coast phenomenon. Long, heavy, and all muscle, they were originally marketed and sold West of the Mississippi River while the lighter, more compact sidewinder circular saws were sold East of the Mississip.
But, to reduce one of the greatest economic forces since supply and demand was invented (globalization) to a bad one-liner, we live in a global world. And that means the river doesn’t have to do with much supply-wise any more and East Coasters have wormdrives on the shelves.
Read more from Mark about the Milwaukee worm drive on Old House Web.