I decided to try this after some recent interest in a wooden "top bar" design. I give it a "3" out of "5", which is about where most of the other wooden stands fall...they all have pros and cons. I'm only posting this to add to the dialog, and maybe help move the hammock stand design state of the art along.
Cheap...<$40, and materials widely available.
Ease of construction...a third grader could build it.
No rail under the back.
I don't like the 1x4 bracing I had to add to obtain the desired stiffness...there was a bit of movement with just the plywood gussets for bracing.
It's kinda fugly.
Legs...2x4x7'...could stand to be a little bit shorter
Plywood (1/2") gussets...16"x16"x ~23"
Bracing...1x4x4'(2) and 1x4x8'(2)
3/8"x6" eyebolt (2) and fender washers (4)
Assorted deck screws